Surgical stapling instrument with a firing member return mechanism

ABSTRACT

A surgical instrument including a firing drive configured to selectively advance a firing member and/or cutting member relative to an end effector and, in addition, a reversing drive configured to selectively retract the firing member and/or cutting member relative to the end effector.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application claiming thebenefit under 35 U.S.C. §120 of co-pending U.S. patent application Ser.No. 12/008,266, entitled SURGICAL STAPLING INSTRUMENT WITH A FIRINGMEMBER RETURN MECHANISM, filed on Jan. 10, 2008, the entire disclosureof which is hereby incorporated by reference herein, which is acontinuation-in-part application claiming the benefit under 35 U.S.C.§120 of co-pending U.S. patent application Ser. No. 11/821,277, entitledSURGICAL STAPLING INSTRUMENTS, filed on Jun. 22, 2007, now U.S. Pat. No.7,753,245, the entire disclosure of which is hereby incorporated byreference herein.

BACKGROUND

1. Field of the Invention

The present invention generally relates to surgical stapling instrumentsand, more particularly, to surgical staplers having a closing system forclosing an end effector and a firing system for deploying staples.

2. Description of the Related Art

As known in the art, surgical staplers are often used to deploy staplesinto soft tissue in order to reduce or eliminate bleeding from the softtissue, especially as the tissue is being transected, for example.Surgical staplers, such as an endocutter, for example, can comprise anend effector which can be moved, or articulated, with respect to anelongate shaft assembly. End effectors are often configured to securesoft tissue between first and second jaw members where the first jawmember often includes a staple cartridge which is configured toremovably store staples therein and the second jaw member often includesan anvil. Such surgical staplers can include a closing system forpivoting the anvil relative to the staple cartridge. These closingsystems, however, do not prevent the end effector from being articulatedrelative to the shaft assembly after the jaw members have been closed.As a result, when the end effector is articulated, the end effector mayapply a shear force to the soft tissue captured between the jaw members.

Surgical staplers, as outlined above, can be configured to pivot theanvil of the end effector relative to the staple cartridge in order tocapture soft tissue therebetween. In various circumstances, the anvilcan be configured to apply a clamping force to the soft tissue in orderto hold the soft tissue tightly between the anvil and the staplecartridge. If a surgeon is unsatisfied with the position of the endeffector, however, the surgeon must typically activate a releasemechanism on the surgical stapler to pivot the anvil into an openposition and then reposition the end effector. Thereafter, staples aretypically deployed from the staple cartridge by a driver which traversesa channel in the staple cartridge and causes the staples to be deformedagainst the anvil and secure layers of the soft tissue together. Often,as known in the art, the staples are deployed in several staple lines,or rows, in order to more reliably secure the layers of tissue together.The end effector may also include a cutting member, such as a knife, forexample, which is advanced between two rows of the staples to resect thesoft tissue after the layers of the soft tissue have been stapledtogether.

After the driver and the cutting member have been advanced within theend effector, it is often necessary to retract the driver and/or cuttingmember to their starting positions. Previous surgical staplers haveincluded a return spring which retracts the cutting member relative tothe staple cartridge after a release button or toggle switch on thesurgical stapler has been actuated by the surgeon, for example. Invarious embodiments, a first end of the return spring can be connectedto the housing of the surgical instrument and a second end of the springcan be connected to the cutting member. Such staplers, however, areoften difficult to use as the force required to extend the return springas the cutting member is advanced is often significant. Furthermore,such return springs often apply a biasing force to the cutting member asit is advanced which can, in various circumstances, prematurely returnthe cutting member, especially in embodiments where multiple strokes ofa trigger are required to completely advance the cutting member. What isneeded is an improvement over the foregoing.

SUMMARY

In at least one form, a surgical instrument can comprise an endeffector, a firing member, a trigger, a firing drive selectivelyengageable with the firing member, wherein the firing drive comprises arack. The rack can comprise a first drive portion, wherein the firingdrive is configured to engage the first drive portion and advance thefiring member relative to the end effector upon a first actuation of thetrigger, a second drive portion, wherein the firing drive is configuredto engage the second drive portion and advance the firing memberrelative to the end effector upon a second actuation of the trigger, anda rotatable portion configured to be rotated a first amount during thefirst actuation of the trigger and a second amount during the secondactuation of the trigger, wherein the rotatable portion comprises a keypositionable in an initial position, and wherein the rotatable portionmay be configurable in an activated configuration and a deactivatedconfiguration. The surgical instrument can further comprise a reversingdrive selectively engageable with the rack, wherein the reversing driveis configured to retract the rack and the firing member relative to theend effector upon a subsequent actuation of the trigger, and wherein thesubsequent actuation is subsequent to the second actuation. The surgicalinstrument can comprise an indexing member comprising a first stop,wherein the key is configured to rotate past the first stop into a firstposition during the first actuation of the trigger, and wherein thefirst stop is configured to prevent the key from returning to itsinitial position when the rotatable portion is in its activatedconfiguration, and a second stop, wherein the key is configured torotate past the second stop into a second position during the secondactuation of the trigger, wherein the second stop is configured toprevent the key from returning to the first position when the rotatableportion is in the activated configuration, and wherein the key isconfigured to rotate past the second stop and the first stop when therotatable portion is in its deactivated configuration and the key isreturned to its initial position.

In at least one form, a surgical instrument can comprise an endeffector, a firing member movable between an initial position, a firstfired position, and a second fired position, a trigger, and a firingdrive selectively engageable with the firing member, wherein the firingdrive comprises a rack. The rack can comprise a first drive portion,wherein the firing drive is configured to engage the first drive portionand advance the firing member relative to the end effector upon a firstactuation of the trigger, and a second drive portion, wherein the firingdrive is configured to engage the second drive portion and advance thefiring member relative to the end effector upon a second actuation ofthe trigger. The surgical instrument can further comprise a reversingdrive selectively engageable with the rack, wherein the reversing driveis configured to retract the rack and the firing member relative to theend effector upon a subsequent actuation of the trigger, and wherein thesubsequent actuation is subsequent to the second actuation. The surgicalinstrument can further comprise holding means for holding the firingdrive in the first position after the first actuation and before thesecond actuation and for holding the firing drive in the second positionafter the second actuation and before the subsequent actuation.

In at least one form, a surgical instrument can comprise a shaftcomprising a distal end, a firing member, a trigger, and a firing driveselectively engageable with the firing member, wherein the firing drivecomprises a first drive portion, wherein the firing drive is configuredto engage the first drive portion and advance the firing member relativeto the distal end upon a first actuation of the trigger, and a seconddrive portion, wherein the firing drive is configured to engage thesecond drive portion and advance the firing member relative to thedistal end upon a second actuation of the trigger, and a rotatableportion configured to be rotated a first amount during the firstactuation of the trigger and a second amount during the second actuationof the trigger, wherein the rotatable portion comprises a keypositionable in an initial position. The surgical instrument cancomprise a reversing drive selectively engageable with the firingmember, wherein the reversing drive is configured to retract the firingmember relative to the distal end upon a subsequent actuation of thetrigger, and wherein the subsequent actuation is subsequent to thesecond actuation. The surgical instrument can further comprise a holdingmember comprising a first backstop, wherein the key is configured torotate past the first backstop into a first position during the firstactuation of the trigger, wherein the first backstop is configured toprevent the key from returning to its initial position prior to thereversing drive being engaged with the firing member, and a secondbackstop, wherein the key is configured to rotate past the secondbackstop into a second position during the second actuation of thetrigger, wherein the second backstop is configured to prevent the keyfrom returning to its first position prior to the reversing drive beingengaged with the firing member, and wherein the reversing drive isconfigured to disengage the key from the holding member when thereversing drive is engaged with the firing member.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention itself will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is an elevational view of a surgical instrument in accordancewith an embodiment of the present invention;

FIG. 2 is an elevational view of a handle portion of the surgicalinstrument of FIG. 1;

FIG. 3 is an elevational view of an end effector of the surgicalinstrument of FIG. 1;

FIG. 4 is a top view of the end effector of FIG. 3;

FIG. 5 is a perspective view of an articulation joint of the surgicalinstrument of FIG. 1 with some components of the surgical instrumentremoved;

FIG. 6 is a perspective view of an elongate shaft assembly and thearticulation joint of the surgical instrument of FIG. 1 with somecomponents of the surgical instrument removed;

FIG. 7 is a partial perspective view of the handle portion and theelongate shaft assembly of the surgical instrument of FIG. 1 with somecomponents of the surgical instrument removed;

FIG. 8 is an elevational view of the handle portion of FIG. 2 with somecomponents of the surgical instrument removed;

FIG. 9 is an elevational view of the handle portion of FIG. 2 withadditional components of the surgical instrument removed;

FIG. 10 is an elevational view of an actuator of an articulation lockingmechanism and an end effector closure system of a surgical instrument inaccordance with an alternative embodiment of the present invention withsome components of the surgical instrument removed;

FIG. 11 is an elevational view of the surgical instrument of FIG. 10illustrating the articulation locking mechanism actuator in an unlockedposition and the end effector closure system in an open configuration;

FIG. 12 is an elevational view of the surgical instrument of FIG. 10illustrating the articulation locking mechanism actuator in an unlockedposition and the end effector closure system in a partially closedconfiguration;

FIG. 13 is an elevational view of the surgical instrument of FIG. 10illustrating the articulation locking mechanism actuator in a lockedposition and the end effector closure system in a closed configuration;

FIG. 14 is an elevational view of a closure trigger of an end effectorclosure system of the surgical instrument of FIG. 1;

FIG. 15 is a partial perspective view of the closure trigger of FIG. 15;

FIG. 16 is a partial elevational view of the closure trigger of FIG. 15;

FIG. 17 is a perspective view of a trigger lock of the surgicalinstrument of FIG. 1;

FIG. 18 is an elevational view of the trigger lock of FIG. 17;

FIG. 19 is a detail view of a firing drive of the surgical instrument ofFIG. 1 with some components of the surgical instrument removed;

FIG. 20 is a perspective view of the firing drive of FIG. 19;

FIG. 21 is a partial detail view of a firing trigger, pawl, and tiltermechanism of the firing drive of FIG. 19;

FIG. 22 is an elevational view of the pawl, tilter mechanism, and a pawlreturn spring of the firing drive of FIG. 19;

FIG. 23 is an elevational view of the pawl of FIG. 22;

FIG. 24 is a detail view of the firing drive of FIG. 19 illustrating thepawl pivoted into a position to engage a firing link of the firingdrive;

FIG. 25 is a perspective view of the tilter mechanism of FIG. 22;

FIG. 26 is a perspective view of a frame of the surgical instrument ofFIG. 1;

FIG. 27 is a detail view of a firing drive of a surgical instrument inaccordance with an alternative embodiment of the present invention withsome components of the surgical instrument removed;

FIG. 28 is a detail view of the firing drive of FIG. 27 illustrating apawl of the firing drive disengaged from a firing link;

FIG. 29 is a perspective view of a return mechanism of the surgicalinstrument of Claim 1 illustrating the firing trigger in an unactuatedposition with some components of the surgical instrument removed;

FIG. 30 is a partial perspective view of the return mechanism of FIG. 29illustrating the firing trigger in an actuated position with somecomponents of the return mechanism removed;

FIG. 31 is an elevational view of the return mechanism of FIG. 29arranged in the configuration illustrated in FIG. 30;

FIG. 32 is an elevational view of the return mechanism of FIG. 29illustrating a return carriage of the return mechanism in an actuatedposition;

FIG. 33 is a partial perspective view of the return mechanism of FIG. 29with some components of the return mechanism removed;

FIG. 34 is a perspective view of the pawl and firing pin of the firingdrive of FIG. 19;

FIG. 35 is a perspective view of the return mechanism of FIG. 29illustrating the return carriage in an actuated position and the firingtrigger returned to its unactuated position;

FIG. 36 is a partial perspective view of the return mechanism of FIG. 29arranged in the configuration illustrated in FIG. 35 illustrating areturn pin of the return mechanism operably engaged with the firingtrigger;

FIG. 37 is a partial perspective view of the return mechanism of FIG. 29illustrating the firing trigger in an actuated position after rotatingthe return pin;

FIG. 38 is an additional perspective view of the return mechanism ofFIG. 29 arranged in the configuration illustrated in FIG. 37;

FIG. 39 is a partial perspective view of the return mechanism of FIG. 29illustrating the firing trigger returned to its unactuated position;

FIG. 40 is a perspective view of the return mechanism of FIG. 29illustrating the return carriage returned to its unactuated position;

FIG. 41 is a perspective view of the return mechanism of FIG. 29arranged in the configuration of FIG. 40 illustrating the relativerelationship between a biasing spring and the return pin of the returnmechanism with some components of the return mechanism removed;

FIG. 42 is a perspective view of the return mechanism of FIG. 29arranged in the configuration of FIG. 40 illustrating the returncarriage operably engaged with the firing pin of the firing drive andthe return pin of the return mechanism in order to reset the firingdrive and the return mechanism to the their initial configurations;

FIG. 43 is a detail view of a reel of the return mechanism of FIG. 29illustrating the relative relationship between a return band of thereturn mechanism and the stapler frame of FIG. 26;

FIG. 44 is a detail view of the reel of FIG. 43 illustrating therelative relationship between the return band and an alternativeembodiment of the stapler frame of FIG. 26;

FIG. 45 is a perspective view of a return mechanism of a surgicalinstrument in accordance with an alternative embodiment of the presentinvention having an anti-back-up ratchet mechanism;

FIG. 46 is an elevational view of the return mechanism of FIG. 45 havinga return carriage in an unactuated position;

FIG. 47 is a perspective view of the return mechanism of FIG. 45 withsome components of the surgical instrument removed;

FIG. 48 is a perspective view of a return gear, return pin, andanti-back-up pawl of the ratchet mechanism of FIG. 45;

FIG. 49 is another elevational view of the return mechanism of FIG. 45;

FIG. 50 is a perspective view of the articulation joint of FIG. 5;

FIG. 51 is a perspective view of the articulation joint of FIG. 5 withsome components of the surgical instrument removed;

FIG. 52 is a perspective view of the articulation joint of FIG. 5 withadditional components of the surgical instrument removed;

FIG. 53 is a perspective view of a lock member of the end effector ofFIG. 3;

FIG. 54 is another perspective view of the end effector lock member ofFIG. 53;

FIG. 55 is a bottom view of the end effector lock member of FIG. 53;

FIG. 56 is an elevational view of the end effector lock member of FIG.53;

FIG. 57 is a partial perspective view of an articulation joint of aprevious surgical instrument;

FIG. 58 is a perspective view of the articulation joint of FIG. 5 withsome components of the end effector and elongate shaft assembly removed;

FIG. 59 is another perspective view of the articulation joint of FIG. 5with some components of the end effector and elongate shaft assemblyremoved;

FIG. 60 is a perspective view of the end effector lock member of FIG. 53operably engaged with a lock member of the elongate shaft assembly;

FIG. 61 is a perspective view of the shaft assembly lock member of FIG.60;

FIG. 62 is a bottom view of end effector lock member of FIG. 53 operablyengaged with the shaft assembly lock member of FIG. 60;

FIG. 63 is a perspective view of an articulation joint of a surgicalinstrument in accordance with an alternative embodiment of the presentinvention with some components of the surgical instrument removed;

FIG. 64 is a top view of an end effector lock member operably engagedwith a shaft assembly lock member of the surgical instrument of FIG. 63;

FIG. 65 is a perspective view of the end effector lock member operablyengaged with the shaft assembly lock member of FIG. 64;

FIG. 66 is a perspective view of the end effector lock member of FIG.64;

FIG. 67 is an elevational view of the end effector lock member of FIG.64;

FIG. 68 is an elevational view of a surgical instrument in accordancewith an embodiment of the present invention with some components of thesurgical instrument removed;

FIG. 69 is an elevational view of the surgical instrument of FIG. 68illustrating a closure trigger in an actuated position;

FIG. 70 is an elevational view of the surgical instrument of FIG. 68illustrating a firing trigger in an actuated position after a firstactuation of the firing trigger;

FIG. 71 is a perspective view of a gear train of a reversing mechanismof the surgical instrument of FIG. 68 for retracting a firing member;

FIG. 72 is an elevational view of the surgical instrument of FIG. 68illustrating the firing trigger in an unactuated position after it hasbeen released from its first actuation;

FIG. 73 is an elevational view of the surgical instrument of FIG. 68illustrating the firing trigger in an actuated position after a secondactuation of the firing trigger;

FIG. 74 is an elevational view of the surgical instrument of FIG. 68illustrating the firing trigger in an unactuated position after it hasbeen released from its second actuation;

FIG. 75 is an elevational view of the surgical instrument of FIG. 68illustrating the firing trigger in an actuated position after a thirdactuation of the firing trigger;

FIG. 76 is another elevational view of the surgical instrument of FIG.68 illustrating a return carriage of the reversing mechanism after ithas been rotated downwardly into an actuated position;

FIG. 77 is a perspective view of a trigger gear, key gear, and a returnpin of the gear train of the reversing mechanism of FIG. 71;

FIG. 78 is a cross-sectional view of the surgical instrument of FIG. 68illustrating the return pin of FIG. 77 operatively engaged with thetrigger gear and the key gear of the reversing mechanism of FIG. 71;

FIG. 79 is a perspective view of the return pin of FIG. 77;

FIG. 80 is another elevational view of the return carriage of FIG. 76 inan actuated position;

FIG. 81 is a perspective view of a firing pin engaged with a pawl of thefiring drive of the surgical instrument of FIG. 68;

FIG. 82 is an elevational view of the return carriage of the surgicalinstrument of FIG. 68 in an actuated position and the reversingmechanism operably engaged with the firing member;

FIG. 83 is an elevational view of the surgical instrument of FIG. 68illustrating the firing trigger in an actuated position after a fourthactuation which has retracted the firing member;

FIG. 84 is a perspective view of the reversing mechanism of FIG. 76 withsome components removed;

FIG. 85 is an elevational view of the surgical instrument of FIG. 68illustrating the firing trigger in an unactuated position after it hasbeen released from its fourth actuation;

FIG. 86 is an elevational view of the surgical instrument of FIG. 68illustrating the return carriage of FIG. 76 rotated upwardly into anunactuated position and also illustrating the closure trigger in itsunactuated position;

FIG. 87 is a perspective view of a surgical instrument in accordancewith an alternative embodiment of the present invention with somecomponents of the surgical instrument removed;

FIG. 88 is a perspective view of a reversing mechanism of the surgicalinstrument of FIG. 87 including a gear train illustrating the directionsin which the gears of the gear train can rotate when a firing member ofthe surgical instrument is advanced;

FIG. 89 is a perspective view of a trigger gear and a return pin of thereversing mechanism of FIG. 88 illustrating the trigger gear incross-section;

FIG. 90 is another perspective view of the trigger gear and return pinof FIG. 89 illustrating the return pin out of operative engagement withthe trigger gear;

FIG. 91 is a perspective view of the trigger gear and return pin of FIG.89 illustrating the return pin re-engaged with the trigger gear;

FIG. 92 is a perspective view of the reversing mechanism of FIG. 88illustrating the directions in which the gears of the gear train rotatewhen the firing member is retracted;

FIG. 93 is a further perspective view of the reversing mechanism of FIG.88;

FIG. 94 is a perspective view of the surgical instrument of FIG. 87illustrating a trigger lock which is configured to engage a gear of thereversing mechanism of FIG. 88 in addition to the trigger;

FIG. 95 is an elevational view of a reversing mechanism of a surgicalinstrument in accordance with an alternative embodiment of the presentinvention illustrating a return carriage in an unactuated position withsome components of the surgical instrument removed;

FIG. 96 is a perspective view of the reversing mechanism of FIG. 95illustrating a trigger gear having a ratchet face and, in addition, akey gear having a ratchet face with some additional components of thesurgical instrument removed;

FIG. 97 is a cross-sectional view of the reversing mechanism of FIG. 95illustrated in the configuration of FIG. 96;

FIG. 98 is a perspective view of a return pin of the reversing mechanismof FIG. 95;

FIG. 99 is an elevational view of the reversing mechanism of FIG. 95illustrating the return carriage in an actuated position;

FIG. 100 is a perspective view of the reversing mechanism of FIG. 95wherein the ratchet faces of the trigger and key gears are engaged withone another;

FIG. 101 is an elevational view of a surgical instrument in accordancewith an alternative embodiment of the present invention including thefiring drive and the reversing drive of the surgical instrument of FIG.68 with some components of the surgical instrument removed wherein thepawl of the firing drive is illustrated as it would appear when it iswithdrawn relative to the firing member;

FIG. 102 is an elevational view of the surgical instrument of FIG. 101illustrating the pawl operably engaged with the firing member;

FIG. 103 is an elevational view of the surgical instrument of FIG. 101illustrating misalignment between the pawl and a recess in the firingmember when the firing member unintentionally backs-up relative to itsintended position;

FIG. 104 is an elevational view of a surgical instrument in accordancewith an alternative embodiment of the present invention including ananti-backup mechanism with some components of the surgical instrumentremoved;

FIG. 105 is a perspective view of a return pin of the anti-backupmechanism of FIG. 104;

FIG. 106 is a detail view of a key extending from the return pin of FIG.105;

FIG. 107 is a perspective view of an indexing element of the anti-backupmechanism of FIG. 104;

FIG. 108 is a perspective view of the return pin of FIG. 105 operablyengaged with the indexing element of FIG. 107;

FIG. 109 is a perspective view of the return pin and the indexingelement illustrating the key of the return pin positioned within a firstaperture in the indexing element;

FIG. 110 a is another perspective view of the return pin key and theindexing element of FIG. 109;

FIG. 110 b is a perspective view of the return pin key depressing theindexing element when the return pin key is moved from the firstaperture to a second aperture of the indexing element;

FIG. 110 c is a perspective view of the key portion of the return pinpositioned within the second aperture of the indexing element;

FIG. 110 d is a perspective view of the return pin key depressing theindexing element when the return pin key is moved from the secondaperture to a third aperture of the indexing element;

FIG. 110 e is a perspective view of the key portion of the return pinpositioned within the third aperture of the indexing element;

FIG. 110 f is a perspective view of the return pin key depressing theindexing element when the return pin key is moved from the thirdaperture to a fourth aperture of the indexing element;

FIG. 110 g is a perspective view of the key portion of the return pinpositioned within the fourth aperture of the indexing element;

FIG. 111 is a cross-sectional view of the indexing element of FIG. 107;

FIG. 112 is a perspective view of an indexing element in accordance withan alternative embodiment of the present invention and a return springoperatively engaged with the indexing element;

FIG. 113 is a cross-sectional view of the indexing element of FIG. 112;

FIG. 114 is a perspective view of an indexing element in accordance withanother alternative embodiment of the present invention;

FIG. 115 is a partial perspective view of a surgical instrumentincluding an anti-backup mechanism in accordance with an alternativeembodiment of the present invention with some components of the surgicalinstrument removed;

FIG. 116 is a cross-sectional view of the anti-backup mechanism of FIG.115;

FIG. 117 is a perspective view of the surgical instrument of FIG. 115illustrating a return carriage of a reversing mechanism in an actuatedposition;

FIG. 118 is a cross-sectional view of the anti-backup mechanism of FIG.115 when the return carriage of FIG. 117 is in its actuated position;

FIG. 119 is a perspective view of a surgical instrument in accordancewith an alternative embodiment of the present invention with somecomponents of the surgical instrument removed to illustrate a switch foractuating a reversing drive of the surgical instrument;

FIG. 120 is a partial elevational view of a surgical instrument inaccordance with another alternative embodiment of the present inventionwith some components of the surgical instrument removed to illustrate aswitch for actuating a reversing drive of the surgical instrument;

FIG. 121 is a partial elevational view of the surgical instrument ofFIG. 120 illustrating a first portion of the switch in an actuatedposition; and

FIG. 122 is a partial elevational view of the surgical instrument ofFIG. 120 illustrating a second portion of the switch utilized toposition the first portion of the switch in its actuated position.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate preferred embodiments of the invention, in one form, and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION

Certain exemplary embodiments will now be described to provide anoverall understanding of the principles of the structure, function,manufacture, and use of the devices and methods disclosed herein. One ormore examples of these embodiments are illustrated in the accompanyingdrawings. Those of ordinary skill in the art will understand that thedevices and methods specifically described herein and illustrated in theaccompanying drawings are non-limiting exemplary embodiments and thatthe scope of the various embodiments of the present invention is definedsolely by the claims. The features illustrated or described inconnection with one exemplary embodiment may be combined with thefeatures of other embodiments. Such modifications and variations areintended to be included within the scope of the present invention.

In various embodiments, a surgical instrument in accordance with thepresent invention can be configured to insert surgical staples into softtissue, for example. In at least one embodiment, referring to FIGS. 1-4,surgical instrument 100 can include handle portion 102, elongate shaftassembly 104, and end effector 106. In various embodiments, referring toFIGS. 3 and 4, end effector 106 can include staple cartridge channel 108and staple cartridge 110, where staple cartridge 110 can be configuredto removably store staples therein. In at least one embodiment, endeffector 106 can further include anvil 112 which can be pivotablyconnected to staple cartridge channel 108 and can be pivoted betweenopen and closed positions by an end effector closure system. In order todeploy the staples from staple cartridge 110, surgical instrument 100can further include a staple driver configured to traverse staplecartridge 110 and a firing drive configured to advance the staple driverwithin the staple cartridge. In various embodiments, anvil 112 can beconfigured to deform at least a portion of the staples as they aredeployed from the staple cartridge. Although various embodiments of anend effector closure system and a firing drive are described in furtherdetail below, several embodiments of end effector closure systems andfiring drives are disclosed in U.S. Pat. No. 6,905,057, entitledSURGICAL STAPLING INSTRUMENT INCORPORATING A FIRING MECHANISM HAVING ALINKED RACK TRANSMISSION, which issued on Jun. 14, 2005, and U.S. Pat.No. 7,044,352, entitled SURGICAL STAPLING INSTRUMENT HAVING A SINGLELOCKOUT MECHANISM FOR PREVENTION OF FIRING, which issued on May 16,2006, the entire disclosures of which are hereby incorporated byreference herein.

In various embodiments, a surgical instrument in accordance with thepresent invention can include a system for moving, or articulating, anend effector relative to an elongate shaft assembly of the surgicalinstrument. In at least one embodiment, referring to FIGS. 3-7, surgicalinstrument 100 can include articulation joint 114 which can movablyconnect end effector 106 and elongate shaft assembly 104. In variousembodiments, articulation joint 114 can permit end effector 106 to bemoved relative to shaft assembly 104 in a single plane or,alternatively, multiple planes. In either event, articulation joint 114can include one or more pivot axes 116 (FIG. 5) about which end effector106 can be articulated. In various embodiments, referring to FIGS. 5 and6, surgical instrument 100 can further include locking mechanism 118which can fix, or lock, the relative relationship between end effector106 and elongate shaft assembly 104. In at least one embodiment, lockingmechanism 118 can include lock member 120 which can be slid relative toend effector 106 and engage end effector 106 in order to prevent, or atleast partially inhibit, relative movement between end effector 106 andshaft assembly 104. In at least one embodiment, lock member 120 can beconfigured to engage at least one of teeth 312 (FIGS. 5 and 6) of endeffector 106 such that the interaction between lock member 120 and teeth312 can prevent, or at least partially inhibit, end effector 106 fromrotating about axis 116 as described in greater detail further below.

In various embodiments, referring to FIGS. 7-9, locking mechanism 118can further include actuator 122 which can be operably connected to lockmember 120. In at least one embodiment, actuator 122 can include pin 124which can be received within slot 121 in lock member 120 such that, whenactuator 122 is slid relative to handle portion 102, pin 124 can abut aside wall of slot 121 and motivate lock member 120 relative to endeffector 106. In at least one embodiment, actuator 122 can be pulledaway from end effector 106, i.e., proximally, to disengage lock member120 from end effector 106. Although not illustrated, other embodimentsare envisioned where actuator 122 can be moved distally, or evenrotated, in order to disengage lock member 120 from end effector 106. Ineither event, locking mechanism 118 can further include return spring126 (FIG. 6) which can be configured to move lock member 120 toward endeffector 106, i.e., distally, to engage lock member 120 with endeffector 106 after actuator 122 has been released. Other lockingmechanisms are disclosed in U.S. patent application Ser. No. 11/100,772,entitled SURGICAL INSTRUMENT WITH ARTICULATING SHAFT WITH SINGLE PIVOTCLOSURE AND DOUBLE PIVOT FRAME GROUND, which was filed on Apr. 7, 2005,U.S. patent application Ser. No. 11/238,358, entitled SURGICALINSTRUMENT WITH ARTICULATING SHAFT WITH RIGID FIRING BAR SUPPORTS, whichwas filed on Sep. 29, 2005, and U.S. patent application Ser. No.11/491,626, entitled SURGICAL STAPLING AND CUTTING DEVICE AND METHOD FORUSING THE DEVICE, which was filed on Jul. 24, 2006, the entiredisclosures of which are hereby incorporated by reference herein.

In various embodiments, referring to FIGS. 1 and 2, actuator 122 can becontoured such that a surgeon can grasp the outer surface of actuator122 and pull actuator 122 proximally as described above. To moveactuator 122, in at least one embodiment, a surgeon may place one handon handle grip 127, for example, and place their other hand on actuator122 so that the surgeon can move actuator 122 relative to handle grip127. In other various embodiments, referring to FIGS. 10-13, actuator122′ can be configured such that a surgeon may only need one hand tooperate the surgical instrument. More particularly, in at least oneembodiment, actuator 122′ can include hooks, or projections, 115extending therefrom which can allow the surgeon to hold handle grip 127with one hand and extend at least one finger from that hand distally togrip at least one projection 115 and pull actuator 122′ proximally asdescribed above. While actuator 122′ is described herein as havingprojections 115, actuator 122, or any other suitable actuator, can alsoinclude projections 115 and/or any other suitable features that canassist a surgeon in operating surgical instrument 100 with one hand. Inat least one embodiment, projections 115 can be at least partiallycomprised of and/or coated with an elastic or ‘soft-touch’ materialwhich can improve the surgeon's grip on projections 115 and can provideother ergonomic benefits to the surgeon. In various embodiments,actuator 122′, for example, can be operably engaged with shaft assembly104 such that end effector 106 and shaft assembly 104 can be rotatedabout a longitudinal axis by actuator 122′. In such embodiments, asurgeon can orient end effector 106 in a surgical site by articulatingend effector 106 as described above and/or rotating end effector 106into position. In at least one embodiment, the surgeon can rotateactuator 122′ by positioning a finger against one of projections 115 andapplying a force thereto. In various embodiments, the surgeon can holdactuator 122′ in position by placing a finger against a projection 115and resisting any undesired motion of actuator 122′ and,correspondingly, end effector 106.

In various embodiments, a surgical instrument in accordance with thepresent invention can include a system for closing, or clamping, an endeffector onto soft tissue, for example. In at least one embodiment,referring to FIGS. 2, 5, 8 and 9, surgical instrument 100 can includeclosure trigger 128, drive link 130, driver 132, and closure tube 134.In various embodiments, upon an actuation of closure trigger 128,closure trigger 128 can be configured to displace drive link 130, driver132, and closure tube 134 distally. More particularly, in at least oneembodiment, drive link 130 can include a first end pivotably connectedto trigger 128 and a second end pivotably connected to driver 132 suchthat the rotation of trigger 128 toward handle grip 127 can drive link130 forward and slide driver 132 along an axis defined by driver guide136 (FIG. 8). In various embodiments, driver 132 can include projections133 extending therefrom which can be slidably received within slots 135in driver guide 136 such that slots 135 can define a path for driver 132as it is moved. In various embodiments, closure tube 134 can be operablyengaged with driver 132 such that, when driver 132 is moved distally asdescribed above, closure tube 134 can engage anvil 112 and pivot anvil112 downwardly. Referring primarily to FIG. 5, closure tube 134 can beconfigured to slide over articulation joint 114 and pivot anvil 112relative to staple cartridge 110. In at least one embodiment, asillustrated in FIG. 9, closure tube 134 can include a proximal endhaving projection 135 extending therefrom which can be received in slot131 in driver 132 such that the displacement of driver 132 istransmitted to closure tube 134.

In various embodiments, as described above, locking mechanism 118 canprevent, or at least partially inhibit, relative movement between endeffector 106 and shaft assembly 104. In circumstances where soft tissueis clamped between anvil 112 and staple cartridge 110, for example,relative movement between end effector 106 and shaft assembly 104 canapply a shear force to the soft tissue clamped therebetween which maydamage it. In various embodiments, referring to FIGS. 10-13, in order toprevent, or at least reduce, relative movement between end effector 106and shaft assembly 104 when end effector 106 is closed, the end effectorclosure system can be configured to engage locking mechanism 118 toprevent actuator 122′ from being moved into its unlocked position. Ineffect, in at least one embodiment, the actuation of closure trigger 128can not only close end effector 106, but it can also prevent lockingmechanism 118 from being unlocked. In various embodiments, referring toFIGS. 10-13, surgical instrument 100′ can include driver 132 which canbe configured to abut, or be positioned closely adjacent to, actuator122′ when driver 132 is moved distally by trigger 128 and therebyprevent actuator 122′ from being moved proximally as described abovewith respect to actuator 122. More particularly, before trigger 132 isactuated, as illustrated in FIGS. 10 and 11, actuator 122′ can be slidproximally in order to slide lock member 120 relative to end effector106 and unlock articulation joint 114. Upon an actuation of trigger of132, however, referring to FIG. 13, driver 132 can be configured toabut, or be positioned adjacent to, actuator 122′ such that actuator122′ cannot be moved proximally to disengage lock member 120 from endeffector 106. As a result, the end effector closure system can preventend effector 106 from being articulated after it has been closed,thereby reducing the possibility that a shear force will be transmittedto the soft tissue clamped therein.

Further to the above, the end effector closure system can providefeedback to the surgeon that the end effector has been closed and, inorder for the surgeon to unlock and articulate the end effector, thesurgeon must first at least partially re-open the end effector beforethe end effector can be articulated. More particularly, owing to theinteraction between driver 132 and actuator 122′ when end effector 106is closed, when a surgeon attempts to pull actuator 122′ proximally tounlock articulation joint 114, driver 132 can substantially preventactuator 122′ from moving thereby signaling to the surgeon that endeffector 106 is closed and end effector 106 must first be opened beforeactuator 122′ can be moved and the articulation joint can be unlocked.In various embodiments, such an end effector closure system can preventthe surgeon from damaging the surgical instrument and/or tissue capturedwithin, or surrounding, the end effector. More particularly, in at leastone embodiment, when closure tube 134 has been advanced to close anvil112 as described above, closure tube 134 may apply a force to anvil 112to maintain anvil 112 in a closed position and, in variouscircumstances, this force can create friction forces within articulationjoint 114 which can inhibit, if not prevent, end effector 106 fromrotating about articulation joint 114. In embodiments without the endeffector closure system described above, if a surgeon attempts toovercome these friction forces without first at least partially openingthe end effector, the surgeon may bend or break one or more componentsof the surgical instrument, for example. In various embodiments of thepresent invention, however, driver 132, for example, may prevent thesurgeon from releasing articulation lock 120 as described above and, asa result, the surgeon may not be afforded the opportunity to unlockarticulation joint 114 let alone articulate end effector 106.

In various embodiments, a surgical instrument in accordance with thepresent invention can include an end effector closure system which canposition anvil 112, for example, in an open position, a closed position,and a partially closed position. In at least one embodiment, a surgeoncan move an anvil 112 into a partially closed position and evaluatewhether the end effector should be repositioned or articulated beforeanvil 112 is moved into its closed position. In such embodiments, anvil112 can be moved relative to soft tissue positioned intermediate anvil112 and staple cartridge 110 without applying a shear force, or at leasta substantial shear force, to the soft tissue before anvil 112 iscompletely closed. In at least one embodiment, anvil 112 can beconfigured such that it does not clamp the soft tissue positionedbetween anvil 112 and staple cartridge 110 when it is in its partiallyclosed position. Alternatively, anvil 112 can be configured to apply alight clamping force to the soft tissue when anvil 112 is in itspartially closed position before applying a larger clamping force whenit is moved into its closed position. In at least one such embodiment,the surgical instrument can include a trigger which can be moved betweena first position (FIG. 11) which corresponds to the open position ofanvil 112, a second position (FIG. 12) which corresponds with itspartially closed position, and a third position (FIG. 13) whichcorresponds with its closed position. In various embodiments, referringto FIGS. 8 and 9, trigger 128 can be pivotably mounted to housing 103 ofhandle portion 102 such that trigger 128 can be rotated about pin 129between its first, second, and third positions. In various embodiments,referring to FIGS. 8, 9, 17 and 18, surgical instrument 100 can furtherinclude trigger lock 148 which can be configured to engage trigger 128and selectively lock trigger 128 in at least one of its first, second,and third positions described above. In at least one embodiment, trigger128 can include pivot end 138 comprising cam surface 140, first notch142, and second notch 144 where trigger lock 148 can be configured toengage first notch 142 and second notch 144. More particularly, surgicalinstrument 100 can further include, referring to FIGS. 8 and 9, triggerlock spring 150 which can be configured to bias follower portion 149 oftrigger lock 148 against cam surface 140 such that when either firstnotch 142 or second notch 144 is aligned with follower portion 149,trigger lock spring 150 can push follower portion 149 into first notch142 or second notch 144, respectively. In at least one embodiment,referring primarily to FIGS. 8 and 9, trigger lock 148 can be pivotablymounted to housing 103 of handle portion 102 via pin 151. In variousembodiments, trigger lock spring 150 can be compressed intermediatebutton portion 152 of trigger lock 148 and housing 103 such that triggerlock spring 150 can rotate trigger lock 148 about pin 151 and biastrigger lock 148 downwardly against cam surface 140 of trigger 128.

Further to the above, in at least one embodiment, first notch 142 can bealigned with follower portion 149 when trigger 132 is moved into itssecond position and anvil 112 is moved into its partially closedposition. In various embodiments, follower portion 149 can be securelyretained within first notch 142 such that trigger lock 148 may need tobe manually disengaged from trigger 132 before trigger 132 can be movedinto its third position and/or returned to its first position. In atleast one embodiment, referring to FIGS. 8 and 9, a surgeon can depressbutton portion 152 of lock member 148 such that lock member 148 isrotated about pin 151 and follower portion 149 is lifted upwardly andout of engagement with trigger 128. In other various embodiments, firstnotch 142 can be configured such that follower portion 149 can slide outof first notch 142 upon an application of force to trigger 132. Ineither event, after follower portion 149 has been disengaged from firstnotch 142, a surgeon can selectively move trigger 132 into its thirdposition or release trigger 132 and allow a trigger spring, for example,to return trigger 132 to its first position. In at least one alternativeembodiment, first notch 142 and follower portion 149 can be configuredsuch that, after trigger 132 has been moved into its second position,trigger 132 must be moved into its third position before it can bereturned into its first position. In either event, in at least oneembodiment, second notch 144 of trigger 132 can be aligned with followerportion 149 when trigger 132 is moved into its third position and anvil112 is moved into its closed position. Similar to first notch 142,second notch 144 can be configured to retain follower portion 149therein until lock member 148 is disengaged from trigger 132 and/or asufficient force is applied to trigger 132 to dislodge follower portion149 from second notch 144. Thereafter, in various embodiments, a triggerspring can move trigger 132 from its third position into its secondposition where the surgeon may be required to, similar to the above,disengage follower portion 149 from first notch 142. In at least onealternative embodiment, first notch 142 can be configured such thatfollower portion 149 can slide past first notch 142 and allow trigger132 to be moved from its third position to its first position withoutrequiring the surgeon to dislodge follower portion 149 from first notch142.

Further to the above, although not illustrated, button portion 152 oflock member 148 can be recessed, for example, within surgical instrumenthousing 103 when closure trigger 128 is in its first position. Inalternative embodiments, button portion 152 can be positioned flushlywith housing 103 or it can extend slightly from housing 103. In eitherevent, in at least one embodiment, button portion 152 can move outwardlyrelative to housing 103 when closure trigger 128 is moved into itssecond position. Such movement can provide visual feedback to thesurgeon that the anvil of the surgical instrument is in its partiallyclosed position. In addition, the movement of button portion 152 canalso be accompanied by audio and/or tactile feedback. In either event, asurgeon can access button portion 152 after it has been moved outwardlysuch that lock member 148 can be disengaged from trigger 128 asdescribed above. In various embodiments, button portion 152 can moveoutwardly even further when trigger 128 is moved from its secondposition to its third position. Similar to the above, such movement canprovide a visual cue to the surgeon that the anvil is now in its closedposition and can be accompanied by audio and/or tactile feedback, asdescribed above. Although button 152 is described above as movingoutwardly as trigger 128 is progressed between its first and thirdpositions, the invention is not so limited. On the contrary, button 152,or any other suitable indicator, can be provide feedback to the surgeonin any suitable manner.

In alternative embodiments, although not illustrated, anvil 112 can beheld, or retained, in more than the three positions described above,i.e., its open, closed, and partially-closed positions. In at least oneembodiment, anvil 112 can be retained in open, closed, and two or moreintermediate positions. In such embodiments, anvil 112 could beprogressed through these intermediate positions and apply anincreasingly greater force to the soft tissue captured in end effector106 as anvil 112 is moved toward its closed position. In at least oneembodiment, similar to the above, trigger 132 could include a pluralityof notches which could correspond with the various intermediatepositions of anvil 112. In various alternative embodiments, although notillustrated, the end effector closure system could include a ratchetassembly which could allow trigger 132 and, correspondingly, anvil 112to be held in a plurality of positions. In such embodiments, anvil 112and trigger 132 could be held in place by a pawl pivotably engaged witha ratchet wheel operably engaged with trigger 132.

In various embodiments, referring to FIGS. 10-13, the relative movementbetween actuator 122′ and handle portion 102′, as described above, canbe limited in order to control the range through which lock member 120can be displaced. More particularly, referring to FIGS. 10 and 11, thedistal portion of actuator 122′ can include projection 123 extendingtherefrom which can be received in cavity 125 where the displacement ofactuator 122′ can be limited by proximal wall 117 and distal wall 119 ofcavity 125. In at least one embodiment, when trigger 128 is in its firstposition, as illustrated in FIGS. 10 and 11, actuator 122 can be movedfrom a distal position in which projection 123 can abut distal wall 119,as illustrated in FIG. 10, into a more proximal position in whichprojection 123 does not abut distal wall 119, as illustrated in FIG. 11.In this more distal position, as described above, lock member 120 can bedisengaged from end effector 106 and end effector 106 can be rotatedrelative to shaft assembly 104. When trigger 128 is in its secondposition, referring to FIG. 12, driver 132 can limit the range of motionof actuator 122′ such that projection 123 cannot be positioned againstproximal wall 117. In at least one embodiment, however, actuator 122′can be moved proximally a sufficient distance to disengage lock member120 from end effector 106. In these circumstances, a surgeon canreposition end effector 106 although anvil 112 may be partially closedonto the soft tissue, for example. When trigger 128 is in its thirdposition, as illustrated in FIG. 13, driver 132 can force actuator 122′distally such that projection 132 abuts, or is positioned adjacent to,distal wall 119 and actuator 122′ cannot be moved sufficiently to unlockarticulation joint 114.

In various embodiments, a surgical instrument in accordance with thepresent invention can include a firing drive configured to advance acutting member and/or staple driver within an end effector as describedabove. In at least one embodiment, referring to FIGS. 8, 9 and 19-25,the firing drive of surgical instrument 100 can include firing trigger160, first firing link 162, second firing link 164, and firing member166. In various embodiments, firing trigger 160 can be operably engagedwith at least one of firing member 166 and firing links 162 and 164 inorder to advance knife bar 168 within elongate shaft assembly 104. In atleast one embodiment, knife bar 168 can be operably engaged with acutting member (not illustrated) and a staple driver (not illustrated)in end effector 106 where the cutting member can be configured to incisetissue, for example, and the staple driver can be configured to deploystaples from staple cartridge 110. Cutting members and staple driversare well disclosed in U.S. Pat. Nos. 6,905,057 and 7,044,352, which havebeen previously incorporated by reference into the present application,and, as a result, these devices are not described in greater detailherein. Other cutting members and staple drivers are disclosed in U.S.patent application Ser. No. 11/541,123, entitled SURGICAL STAPLES HAVINGCOMPRESSIBLE OR CRUSHABLE MEMBERS FOR SECURING TISSUE THEREIN ANDSTAPLING INSTRUMENTS FOR DEPLOYING THE SAME, which was filed on Sep. 29,2006, and U.S. patent application Ser. No. 11/652,169, entitled SURGICALSTAPLING DEVICE WITH A CURVED CUTTING MEMBER, which was filed on Jan.11, 2007, the entire disclosures of which are hereby incorporated byreference herein.

In various embodiments, referring primarily to FIGS. 19 and 20, firingtrigger 160 can be pivotably connected to surgical instrument housing103 (FIGS. 8 and 9) by pin 161. In use, in at least one embodiment,firing trigger 160 can be pivoted about pin 161 in order to advancefiring member 166 and firing links 162 and 164 distally. In variousembodiments, firing trigger 160 can include slots 159, where slots 159can be configured to receive firing pin 172. In various embodiments,when firing trigger 160 is actuated, or rotated, from its positionillustrated in FIG. 2 to a position adjacent handle grip 127, the sidewalls of slots 159 can be configured to engage and advance firing pin172 distally. In at least one embodiment, referring to FIG. 23, thefiring drive can further include pawl 170, where pawl 170 can includeaperture 171. In various embodiments, aperture 171 can be configured toreceive at least a portion of firing pin 172 such that, when firing pin172 is advanced distally by trigger 160, firing pin 172 can advance pawl170 distally as well. In various embodiments, referring to FIG. 24, pawl170 can include tooth 174 and firing member 166 can include recess 167,where recess 167 can be configured to receive tooth 174. In use, whenpawl 170 is advanced distally by firing pin 172 and tooth 174 is engagedwith a side wall of recess 167, pawl 170 can advance firing member 166distally as well. In various embodiments, pawl 170 can be advanceddistally by firing pin 172 along a substantially linear path. In suchembodiments, slots 159 can include arcuate profiles which can, incooperation with firing pin 172, convert the rotational motion of firingtrigger 160 into translational motion of pawl 170. In at least oneembodiment, the force applied to pawl 170 can be substantially, if notentirely, directed in the distal direction. In such embodiments, as aresult, the possibility of pawl 170 becoming bound or stuck againststapler frame 184 can be reduced.

In various embodiments, pawl 170 can be pivoted between a first positionin which pawl 170 is operably disengaged from firing member 166 and asecond position, referring to FIGS. 19 and 20, in which pawl 170 isoperably engaged with firing member 166. Referring primarily to FIGS.21-25, the firing drive can further include tilter mechanism 178 whichcan be configured to pivot pawl 170 between its first and secondpositions. In use, when firing trigger 160 is actuated, pawl 170 can bemoved, at least initially, relative to tilter mechanism 178 such that atleast a portion of pawl 170 can abut tilter mechanism 178 and pivot pawl170 upwardly and into operative engagement with firing member 166. In atleast one embodiment, pawl 170 can include, referring primarily to FIG.23, groove 175 which can be configured to receive projection 179 (FIG.25) extending from the center portion of tilter mechanism 178. In atleast one embodiment, as pawl 170 is advanced distally, proximal wall176 of groove 175 can contact a cam surface on projection 179 and, owingto the force applied to pawl 170 by pivot pin 172, pawl 170 can bepivoted, or rotated, upwardly such that tooth 174 can be positioned inrecess 167 of firing member 166 as described above. After pawl 170 hasbeen pivoted, pawl 170 can drag tilter mechanism 178 distally as pawl170 is advanced toward end effector 106. More particularly, in at leastone embodiment, tilter mechanism 178 can include deformable members 180which can be received within slots 182 in stapler frame 184 such thatthe interaction between deformable members 180 and stapler frame 184 atleast partially inhibits the movement of tilter mechanism 178 relativeto stapler frame 184. Stated another way, owing to static frictionforces between deformable members 180 and the side walls of slots 182, aforce sufficient to overcome these friction forces must be applied totilter mechanism 178 before tilter mechanism 178 can be ‘dragged’relative to stapler frame 184.

After firing trigger 160 has been actuated and firing member 166 hasbeen advanced, trigger 160 can be released and returned to itsunactuated position illustrated in FIG. 2 and pawl 170 can be disengagedfrom firing member 166 and retracted to its starting positionillustrated in FIG. 19. More particularly, in at least one embodiment,surgical instrument 100 can further include a trigger spring (notillustrated) operably engaged with trigger 160 and housing 103, forexample, where the trigger spring can be configured to rotate trigger160 about pin 161 and drive firing pin 172 proximally after pawl 170 hasbeen disengaged from firing member 166. In various embodiments, pawl 170can be disengaged from firing member 166 when it is pivoted from itssecond position, as illustrated in FIG. 24, into its first position, asdescribed above, by tilter mechanism 178. In such embodiments, pawl 170can be moved, at least initially, relative to tilter mechanism 178 suchthat distal wall 177 of groove 175 can contact a second cam surface onprojection 179 and can, owing to a force applied to firing pin 172 bytrigger 160 or return spring 186, rotate pawl 170 downwardly such thattooth 174 of pawl 170 can be disengaged from recess 167 in firing member166. Thereafter, trigger 160 and/or return spring 186 can pull, orretract, pawl 170 relative to firing member 166. In various embodiments,similar to the above, pawl 170 can be configured to drag tiltermechanism 178 proximally within slot 182. As a result of the above, pawl170 does not need to be biased into its first or second positions. Invarious circumstances, pawl 170 can be rotated freely between its firstand second positions without having to overcome a force applied theretoby a biasing spring. In effect, in various embodiments, the force tomove pawl 170 between its first and second positions need only overcomethe gravitational weight of pawl 170 and any frictional forces betweenpawl 170 and the surrounding components of the surgical instrument.

Once pawl 170 has been returned to its original position, in at leastone embodiment, tooth 174 of pawl 170 may no longer be aligned withrecess 167 in firing member 166. On the contrary, referring generally toFIGS. 19 and 20, tooth 174 of pawl 170 can be aligned with recess 163 infirst firing link 162. More particularly, first firing link 162 can bepivotably connected to firing member 166 such that, when firing member166 is advanced distally, as described above, firing member 166 can pullfirst firing link 162 into the position that firing member 166previously occupied. As a result, upon a second actuation firing trigger160, pawl 170 can be pivoted from its first position into its secondposition such that tooth 174 is operably engaged with recess 163 andpawl 170 can advance firing link 162 distally. In at least oneembodiment, firing link 162 can push firing member 166 and knife bar 168distally and, correspondingly, advance the cutting member and the stapledriver distally within end effector 106. Thereafter, pawl 170 can onceagain be pivoted from its second position to its first position and canbe retracted relative to first firing link 162. Once pawl 170 isreturned to its original position for the second time, tooth 174 of pawl170 may no longer be aligned with recess 163 of first firing link 162.On the contrary, similar to the above, tooth 174 can be aligned withrecess 165 in second firing link 164 and the process described above canbe repeated.

Although not illustrated, a surgical instrument in accordance with thepresent invention can include more than two, or less than two, firinglinks in order to advance the cutting member and staple driver to theirdesired positions within end effector 106. In various embodiments, asdescribed in greater detail below, firing member 166 can include morethan one recess 167 such that pawl 170 can directly advance firingmember 166 toward end effector 106 more than once. In at least one suchembodiment, pawl 170 can be retracted after advancing firing member 166distally, as described above, such that, when pawl 170 is once againtilted upwardly, pawl 170 can engage another recess 167 in firing member166 and advance firing member 166 toward end effector 106 once again. Asa result, in at least one embodiment, firing links 162 and 164 may notbe required.

In various embodiments, a surgical instrument can include one or morespring members configured to move pawl 170 into at least one of itsfirst and second positions. In at least one embodiment, referring toFIGS. 27 and 28, the firing drive can include pawl 170′, firing pin 172,and tilter mechanism 178′ where, similar to the above, tilter mechanism178′ can be configured to pivot pawl 170′ upwardly when pawl 170′ isadvanced distally. The firing drive can further include pivot spring 188which can be operably connected to pawl 170′ such that, when pawl 170′is pivoted upwardly into its second position as illustrated in FIG. 27,pawl 170′ can flex, or resiliently bend, pivot spring 188. After pawl170′ has been advanced, pawl 170′ can be pivoted downwardly into itsfirst position by pivot spring 188 as illustrated in FIG. 28. Moreparticularly, owing to potential energy stored in pivot spring 188 whenit is flexed, spring 188 can move pawl 170′ downwardly once pawl 170′ isno longer held in its second position by tilter mechanism 178′ andfiring pin 172. Thereafter, as described above, pawl 170′ can beretracted relative to firing member 166 and/or firing links 162 and 164.In various embodiments, tilter mechanism 178′ may not include a secondcam surface for pivoting pawl 170 into its first position. In suchembodiments, pawl 170′ can be retracted by a force applied to firing pin172 as described above. In various alternative embodiments, although notillustrated, tilter mechanism 178′ and pawl 170′ can also includeco-operating features for pivoting pawl 170′ downwardly into its firstposition.

In various embodiments, referring to FIGS. 19 and 20, surgicalinstrument 100 can further include band 190 which can be configured tomove firing member 166 and firing links 162 and 164 relative to endeffector 106. In at least one embodiment, a first end of band 190 can beconnected to firing member 166, for example, such that, when firingmember 166 is advanced distally, band 190 can be pulled distally aswell. In various alternative embodiments, band 190 can be connected tofirst firing link 162 and/or second firing link 164. In at least oneembodiment, band 190 can be positioned around at least a portion ofreel, or spool, 192 such that when band 190 is pulled by firing member166, band 190 can be deployed, or unwound, from reel 192. In at leastone embodiment, a second end of band 190 can be connected to reel 192such that band 190 cannot be readily disengaged from reel 192 under thenormal operating conditions of surgical instrument 100. In either event,when band 190 is pulled by firing member 166, reel 192 can be rotated inone of a clockwise or counter-clockwise direction, depending on themanner in which band 190 is positioned around reel 192. In order toretract firing member 166, reel 192 can be rotated in an oppositedirection to move firing member 166, and firing links 162 and 164,proximally and wind band 190 around reel 192.

In various embodiments, band 190 can be wound around reel 192 such thatband 190 is wrapped around a substantially cylindrical surface on reel192. In at least one embodiment, the distance between an axis ofrotation of reel 192 and the cylindrical surface can be substantiallyequidistant around the perimeter of reel 192. In these embodiments, themechanical advantage of reel 192 can remain substantially constant asband 190 is pulled proximally as described above and the capacity forreel 192 to apply a pulling force to band 190 can remain substantiallythe same. In alternative embodiments, however, reel 192 can beconfigured to provide a variable mechanical advantage. In at least oneembodiment, reel 192 can include a non-cylindrical surface on which band190 can be wrapped such that the distance between the axis of rotationof reel 192 and the non-cylindrical surface is not equidistant aroundthe perimeter of reel 192. In these embodiments, as a result, thecapacity for reel 192 to apply a pulling force to band 190 can change asband 190 is wound around reel 192. In at least one embodiment, reel 192can act as a cam and can include a shape which can be optimized toprovide additional force to band 190 when it is initially retracted,i.e., when the force to retract the cutting member, for example, can beat its highest.

In various embodiments, referring to FIGS. 29-42, firing trigger 160 canbe selectively engaged with a return mechanism of surgical instrument100. In at least one embodiment, when firing trigger 160 is operablyengaged with firing member 166 via pawl 170, as described above, anactuation of firing trigger 160 can advance firing member 166 distallyand, when firing trigger 160 is operably engaged with firing member 166via band 190, an actuation of firing trigger 160 can retract firingmember 166 proximally. In various embodiments, the return mechanism canbe manually actuated to disengage firing trigger 160 from firing member166 and to operably engage firing trigger 160 with reel 192. In at leastone embodiment, the return mechanism can include return carriage 194which can be pivotably mounted in surgical instrument housing 103 suchthat return carriage 194 can be pivoted between a first, or unactuated,position as illustrated in FIG. 29 and a second, or actuated, positionas illustrated in FIG. 32. In at least one such embodiment, returncarriage 194 can include push button portion 195 which, when a force isapplied thereto, can be configured to move return carriage 194 from itsunactuated position to its actuated position.

When return carriage 194 is positioned in its unactuated positionillustrated in FIGS. 29-31, firing trigger 160 can be configured toadvance firing member 166 as described above and gear portion 158 oftrigger 160 can be operatively engaged with trigger gear 196. In variousembodiments, gear portion 158 and trigger gear 196 can be operablyengaged such that a rotation of trigger 160 about pin 161 can drivetrigger gear 196 about an axis defined by return pin 198. In at leastone embodiment, when return carriage 194 is in its unactuated position,trigger gear 196 can be configured to rotate freely about return pin 198such that the rotation of trigger gear 196 is not transmitted, or atleast not substantially transmitted, to return pin 198. Moreparticularly, referring to FIG. 30, key 199 of return pin 198 can bebiased out of engagement with trigger gear 196 such that the rotation oftrigger gear 196 is not transmitted to key gear 206 and reel 192. As aresult, an actuation of trigger gear 196 does not rotate, or at leastsubstantially rotate, reel 192 when return carriage 194 is in itsunactuated position.

After the cutting member and the staple driver have been advanced withinend effector 106, return carriage 194 can be moved into its actuatedposition. In various embodiments, referring to FIG. 30, reel 192 caninclude cam member 202 extending therefrom which can contact returncarriage 194 and rotate return carriage 194 downwardly. In at least oneembodiment, cam member 202 can contact return carriage 194 during thefinal actuation of trigger 160 which advances the cutting member andstaple driver within end effector 106. In at least one such embodiment,cam member 202 can contact return carriage 194 after the third actuationof firing trigger 160. In various embodiments, referring to FIGS. 32-35,when gear carriage 194 is moved into its actuated position, returncarriage 194 can be configured to operably engage trigger gear 196 withreel 192. In at least one embodiment, referring to FIGS. 33 and 35,return carriage 194 can include biasing spring 200 where, when returncarriage 194 is in its unactuated position, spring 200 can be located inthe position illustrated in FIG. 33 and, when return carriage 194 ismoved into its actuated position illustrated in FIG. 35, spring 200 cancontact return pin 198 and bias return pin 198 toward trigger gear 196.In at least one embodiment, referring to FIG. 31, trigger gear 196 caninclude D-shaped cavity 197 therein which can, under certaincircumstances explained below, receive key 199 extending from return pin198 and operably engage trigger gear 196 with key gear 206 and reel 192.In various embodiments, the movement of return carriage 194 into itsactuated position can be accompanied by an audio and/or tactile feedbackto inform the surgeon that the return mechanism of the surgicalinstrument has been engaged with trigger 160.

Further to the above, when return pin 198 is slid toward trigger gear196, D-shaped cavity 197 can be positioned such that key 199 does notimmediately enter cavity 197. On the contrary, referring to FIG. 31,spring 200 can bias return pin 198 such that key 199 initially abutsface 204 of trigger gear 196. After trigger 160 is released and isreturned to its unactuated position, however, D-shaped cavity 197 can berotated and aligned with key 199 such that spring 200 can bias key 199into cavity 197 as illustrated in FIG. 36. In at least one embodiment,referring to FIG. 31, when return pin 198 is slid toward trigger gear196, an end of return pin 198 can be received in slot 193 in returncarriage 194 as illustrated in FIG. 32. After key 199 has been insertedinto cavity 197, a subsequent actuation of trigger 160 can cause drivesurface 210 of D-shaped cavity 197 to abut key 199 and rotate return pin198 to a position illustrated in FIGS. 37 and 38. In effect, anactuation of trigger 160, in at least one embodiment, can rotate key 199approximately half a revolution such that key 199, which is initiallyextending substantially downwardly (FIG. 36), can be rotated such thatkey 199 is extending substantially upwardly (FIG. 37). Thereafter,trigger 160 can be released and trigger gear 194 can be rotated relativeto key 199 where key 199 can remain oriented in a substantially upwarddirection as illustrated in FIGS. 39-41.

In various embodiments, referring primarily to FIG. 38, key gear 206 canbe operably engaged with return pin 198 such that the rotation of returnpin 198 can be transmitted to key gear 206. In at least one embodiment,key gear 206 can include key-shaped aperture 212 which can be configuredto slidably receive key 199 of return pin 198. In at least one suchembodiment, key 199 can be operably engaged with both recess 197 oftrigger gear 196 and aperture 212 of key gear 206 when return pin 198 isengaged with trigger gear 196. In various alternative embodiments, keygear 206 can be fixedly mounted to return pin 198. In such embodiments,when return pin 198 is slid relative to trigger gear 196, key gear 206can also be slid relative to trigger gear 196. In various embodiments,referring generally to FIG. 38, reel 192 can include spur gear 216mounted thereto, where spur gear 216 can be operatively engaged with keygear 206 such that the rotation of key gear 206 can be transmitted toreel 192. In at least one embodiment, key gear 206, when it is slidtoward trigger gear 196 as described above, can be slid into operativeengagement with reel 192. In alternative embodiments, spur gear 216 canbe configured such that key gear 206 is in operative engagementtherewith regardless of whether key gear 206 has been biased towardtrigger gear 196.

As a result of the above, when return carriage 194 is positioned in itsactuated position illustrated in FIG. 32, an actuation of trigger 160can rotate reel 192 and wind band 190 around at least a portion thereof.In the event that key 199 cannot be operably engaged with trigger gear196 when return carriage 194 is actuated, reel 192 can be rotatedmanually to retract band 190. In at least one such embodiment, referringto FIGS. 33 and 37, bolt, or fastener, 218 can be operatively engagedwith reel 192 such that the rotation of bolt 218 can effect rotation ofreel 192. In various embodiments, a surgeon can insert bolt 218 throughan opening in surgical instrument housing 103 and engage bolt 218 withreel 192. In at least one embodiment, surgical instrument 100 canfurther include a counting mechanism (not illustrated) which can countthe actuations of trigger 160 and, in at least one such embodiment, bolt218, for example, can be operably engaged with the counting mechanism torotate reel 192. In various embodiments, as a result, the surgicalinstrument can include a first, or primary, actuator for winding reel192 and a second actuator which can be configured to wind reel 192 inlieu of the first actuator.

In various embodiments, as described above, reel 192 can be configuredto pull band 190 and retract firing member 166 and firing links 162 and164 proximally. More particularly, as described above, firing member 166and firing links 162 and 164 can be retracted relative to pawl 170 inorder to reposition firing member 166 and firing links 162 and 164 intheir starting positions. In such embodiments, especially in embodimentswhere pawl 170 is pivotable as described above, the return mechanism ofsurgical instrument 100 can be further configured to hold pawl 170 outof operative engagement with firing member 166 and firing links 162 and164 while they are moved relative to pawl 170. More particularly, whenreturn carriage 194 is moved into its actuated position illustrated inFIG. 35, return carriage 194 can be configured to contact an end offiring pin 172 and slide firing pin 172 toward pawl 170 such that firingpin 172 engages pawl 170 and prevents pawl 170 from pivoting upwardly.More particularly, referring to FIG. 34, firing pin 172 can includefirst end 220 which can include a beveled and/or rounded surface, forexample, where, when return carriage 194 contacts first end 220, returncarriage 194 can push firing pin 172 toward pawl 170. In at least oneembodiment, pawl 170 can include recess 173 which can be configured toreceive key 222 extending from firing pin 172 when firing pin 172 ismoved toward pawl 170. When key 222 and recess 173 are operativelyengaged, firing pin 172 can prevent pawl 170 from pivoting upwardly intoengagement with firing member 166 and firing links 162 and 164.

After firing member 166 and firing links 162 and 164 have beenretracted, a new staple cartridge 110 can be secured in end effector 106and surgical instrument 100 can be reset such that it can be used toincise and staple soft tissue once again. In various embodiments,referring to FIGS. 39-42, return carriage 194 can be moved from itsactuated position illustrated in FIG. 32 to its unactuated positionillustrated in FIG. 40. In at least one embodiment, return carriage 194can be rotated, or pivoted, upwardly when a force is applied to buttonportion 195. Alternatively, return carriage 194 can be moved upwardlywhen, referring to FIG. 29, trigger lock 148 is rotated upwardly todisengage follower portion 149 from closure trigger 128 in order toreopen end effector 106 as described above. More particularly, when aforce is applied to button portion 152 of trigger lock 148, trigger lock148 can be rotated upwardly such that projection 147 extending therefromcan contact return carriage 194 and move return carriage 194 upwardly aswell. In either event, referring to FIG. 42, when return carriage 194 ismoved upwardly into is unactuated position, return carriage 194 candisengage firing pin 172 from pawl 170 and, in addition, disengagereturn pin 198 from trigger gear 196. More particularly, return carriage194 can be configured to abut beveled, or rounded, end 221 of firing pin172 such that, when return carriage 194 is rotated upwardly, returncarriage 194 can slide return pin 172 away from pawl 170 and disengagekey 222 from recess 173. Similarly, when return carriage 194 is movedupwardly, a side wall of slot 193 can be configured to contact an end ofreturn pin 198 and slide return pin 198 away from trigger gear 196 todisengage key 199 from D-shaped recess 197. In short, in at least theillustrated embodiment, when button portion 152 of lock member 148 isdepressed and return carriage 194 is moved upwardly, the surgicalinstrument can be reset and can be reused once again.

Although the surgical instruments described above can be reset after thecutting member and staple driver have been completely advanced withinend effector 106, button portion 195 of return carriage 194, forexample, can be depressed after the cutting member and staple driverhave been only partially advanced within end effector 106. In variousembodiments, return carriage 194 can further include guide pin 191extending between opposite sides of return carriage 194. In at least onesuch embodiment, guide pin 191 can be slidably received within guideslot 185 (FIG. 31) in frame 184 such that slot 185 and pin 191 candefine a path for return carriage 194. In various embodiments, guide pin191 and guide slot 185 can be configured to assure that return carriage194 engages firing pin 172 and return pin 198 and resets the surgicalinstrument when return carriage 194 is moved from its actuated positionto its unactuated position as described above.

In various embodiments, surgical instrument 100 can further include abrake for preventing, or at least partially inhibiting, the firing drivefrom advancing and/or retracting the cutting member and staple driver,for example, within end effector 106. In at least one embodiment,referring to FIG. 43, frame 184 can include brake surface 187 wherebrake surface 187 can be configured to apply a braking force to band190. More particularly, when band 190 is pulled proximally and/ordistally as described above, frame 184 can be configured such that band190 slides over brake surface 187 and a friction force is createdtherebetween. In various embodiments, referring to FIG. 44, brakesurface 187′ can be configured such that the path of band 190 betweenfiring member 166 and reel 192 is interrupted by brake surface 187′ anda significant normal force can be applied to band 190.

In at least one embodiment, band 190 can be engaged with brake surface187′ when band 190 is at rest such that a static friction force betweenband 190 and brake surface 187′ can prevent, at least initially, band190 from moving relative to brake surface 187′ when a pulling force isapplied to band 190. When the pulling force applied to band 190 exceedsthe static friction force, band 190 can be moved relative to brakesurface 187′. Such embodiments may be particularly useful when trigger160 is actuated more than one time to advance the cutting member and/orstaple driver within end effector 106. More particularly, after anactuation of trigger 160, pawl 170 can be retracted relative to firingmember 166 as described above and, in various embodiments, the frictionforce between band 190 and brake surface 187′ can prevent, or at leastpartially inhibit, firing member 166 and/or firing links 162 and 164from moving proximally, and/or distally, as pawl 170 is retracted. As aresult of the above, the alignment between tooth 174 of pawl 170 and therecesses in firing member 166 and firing links 162 and 164 can bemaintained when pawl 170 is moved relative thereto.

Similarly, in at least one embodiment, the stiffness of band 190 canalso assist in holding firing member 166 and firing links 162 and 164 inposition. More particularly, in order for firing member 166 to ‘backup’, or move proximally, firing member 166 would have to push band 190proximally and, in effect, wind band 190 around reel 192. In variousembodiments, the stiffness of band 190 can be such that a significantforce to wind band 190 around reel 192 is required and, as a result,firing member 166 can be held in place. To further increase the forcerequired to wind band 190 around reel 192, referring to FIG. 44, thepath of band 190 can be controlled such that is not wound onto reel 192in a tangential direction. More particularly, if the path of band 190 issuch that it is wound onto reel 192 in a non-tangential direction, aportion of the force transmitted through band 190 will be lost thusresulting in a poor mechanical advantage for winding reel 192.

In various embodiments, surgical instrument 100 can include a brakewhich can be engaged with reel 192, or any other suitable component ofthe firing drive, to prevent firing member 166 and/or firing links 162and 164 from being retracted unintentionally, for example. In at leastone embodiment, although not illustrated, the brake can be moved betweena first position and a second position, where, when the brake is in thefirst position, the brake can apply a first braking force to band 190,for example. In at least one such embodiment, the brake can apply, whenit is in the second position, a second braking force to band 190, forexample, which can be greater than or less than the first braking force.In various alternative embodiments, the brake may not be engaged withband 190 or any other portion of the firing drive when the brake is inthe second position. In various embodiments, although not illustrated,surgical instrument 100 can include a detent mechanism which can apply abraking force to reel 192 and/or band 190. In at least one suchembodiment, the detent mechanism can include a ball detent and a springmember for biasingly engaging the ball detent against reel 192 and/orband 190.

In various embodiments, surgical instrument 100 can include a ratchetwhich can allow reel 192 to turn in a first direction but can, invarious circumstances, prevent reel 192 from turning in a directionopposite the first direction. In at least one embodiment, referring toFIGS. 45-49, surgical instrument 100 can include ratchet assembly 230,where ratchet assembly 230 can include ratchet wheel 232 and ratchetpawl 234. In various embodiments, ratchet wheel 232 can operate insubstantially the same way as key gear 206 described above except that,referring primarily to FIGS. 47 and 48, ratchet wheel 232 can includeratchet teeth 236 which can, owing to a ratcheting engagement withratchet pawl 234, prevent ratchet wheel 232 from being turned in aclockwise direction, for example, when return carriage 194′ is in itsunactuated position (FIG. 47). More particularly, each ratchet tooth 236can include a flat surface 240 where, referring to FIG. 48, at least oneof flat surfaces 240 can abut edge 235 of pawl 234 and thereby preventratchet wheel 232 from being rotated in a clockwise direction.

Each ratchet tooth 236 can further include an inclined surface 238,where inclined surfaces 238 can be configured to slide underneath pawl234 when ratchet wheel 232 is turned in a counter-clockwise direction.As a result of the above, ratchet assembly 230 can allow band 190 to bepulled distally by firing member 166, for example, but prevent, or atleast substantially inhibit, band 190 from being moved proximally, atleast when return carriage 194′ is in its unactuated position. Whenreturn carriage 194′ is pivoted downwardly into its actuated position,as described above with regard to return carriage 194, ratchet wheel 232can be slid toward trigger gear 196′ and out of operative engagementwith ratchet pawl 234. Thereafter, as a result, ratchet wheel 232 can berotated in either a clockwise or counter-clockwise direction withoutinterference, or at least substantial interference, from ratchet pawl234. In various alternative embodiments where ratchet wheel 232 is notslid toward trigger gear 196′, ratchet pawl 234 can be moved downwardlyand out of operative engagement with ratchet teeth 236 when returncarriage 194′ is moved into its actuated position. In either event, whenreturn carriage 194′ is in its actuated position, trigger gear 196′ andreturn pin 198′ can rotate ratchet wheel 232 and cam 192′ to retractband 190 and firing member 166.

In various embodiments, referring to FIGS. 68-86, surgical instrument400 can include a closure system for closing the anvil of an endeffector, a firing drive for advancing a firing rod, cutting member,and/or staple driver within the end effector, and a gear-drivenreversing drive for retracting at least one of the firing rod, cuttingmember, and/or staple driver relative to the end effector. In at leastone embodiment, referring to FIG. 68, the closure system can includeclosure trigger 428, drive link 130, and driver 132 where, similar tothe above, closure trigger 428 can be configured to displace drive link130 and driver 132 when closure trigger 428 is moved from its unactuatedposition illustrated in FIG. 68 to its actuated position illustrated inFIG. 69. In various embodiments, the actuation of closure trigger 428can unlock the firing drive. In at least one embodiment, the firingdrive can include firing trigger 460 which, when closure trigger 428 isrotated toward handle 427, can be moved between a locked positionillustrated in FIG. 68 and an unlocked position illustrated in FIG. 69.In at least one such embodiment, closure trigger 428 can include slot,or groove, 128 a which can receive pin, or projection, 160 a extendingfrom firing trigger 460, wherein a sidewall of slot 128 a can beconfigured to prevent pin 160 a, and firing trigger 460, from moving, orat least substantially moving, relative to closure trigger 428 whenclosure trigger 428 is in its unactuated position (FIG. 68). Whenclosure trigger 428 is actuated, or closed, the side wall of slot 128 acan abut pin 160 a and move firing trigger 460 between its lockedposition illustrated in FIG. 68 and its unlocked position illustrated inFIG. 69. In such an unlocked position, slot 128 a can be oriented topermit pin 160 a to move within slot 128 a thereby allowing firingtrigger 460 to move relative to closure trigger 428 and advance thefiring drive as described in greater detail below.

In various embodiments, referring to FIG. 68, the firing drive cancomprise firing trigger 460, firing pin 172, and pawl 170, whereinfiring trigger 460 can be operably engaged with firing rod, or member,466 via pawl 170 and firing pin 172 in order to advance the cuttingmember and the staple driver within the end effector. In at least onesuch embodiment, similar to the above, pawl 170 can be pivoted upwardlyinto engagement with firing member 466 such that, when firing trigger460 is actuated, referring to FIG. 70, firing trigger 460 can advancefiring pin 172, pawl 170, and firing member 466 distally. Thereafter,referring to FIG. 101, pawl 170 can be pivoted downwardly out ofengagement with firing member 466 such that pawl 170 can be retractedproximally relative to firing member 466 when firing trigger 460 isreleased or returned to its unactuated, and unlocked, positionillustrated in FIG. 72. Upon comparing FIGS. 69 and 72, it is readilyapparent that a first cycle of the firing drive has moved firing member466 distally and has also repositioned pawl 170, firing pin 172, andfiring trigger 460 such that firing trigger 460 can be actuated a secondtime to further advance firing member 466. In such circumstances,referring to FIG. 102, pawl 170 can be pivoted upwardly into operativeengagement with firing member 466 and advanced distally by actuatingfiring trigger 460 once again.

In various embodiments, referring to FIGS. 101 and 102, firing member466 can include a plurality of recesses 467 which can each receive atleast a portion of pawl 170 such that pawl 170 can serially engage therecesses 467 in order to advance firing member 466 a plurality of timesas described above. More particularly, in at least one embodiment,firing member 466 can include three recesses 467 which can allow firingmember 466 to be advanced at least three times by trigger 460. By way ofexample, FIG. 73 illustrates the firing drive upon a second actuation oftrigger 460, FIG. 74 illustrates the firing drive after trigger 460 hasbeen returned to its unactuated position after its second actuation,FIG. 75 illustrates the firing drive upon a third actuation of trigger460, and FIG. 82 illustrates the firing drive after trigger 460 has beenreturned to its unactuated position after its third actuation. At suchpoint, as described in greater detail below, the firing drive can bedisengaged from firing member 466 and the reversing drive can beoperably engaged with firing member 466 such that, in variousembodiments, firing member 466 can be retracted relative to the endeffector and the surgical instrument can be reset. Although firingtrigger 460 is actuated three times in order to fully advance firingmember 466 in the illustrated exemplary embodiment, other embodimentsare envisioned which can utilize more than, or less than, three strokesor actuations of the firing trigger.

In various embodiments, as outlined above, surgical instrument 400 canfurther include a gear-driven reversing drive, or mechanism, which canbe configured to retract firing member 466, the cutting member, and/orthe staple driver relative to the end effector of the surgicalinstrument. In at least one embodiment, the reversing mechanism can beoperably engaged with firing member 466, or any other suitable portionof the firing drive, to move firing member 466 proximally. In at leastone such embodiment, referring to FIG. 71, the reversing drive caninclude a gear train comprising trigger gear 496, key gear 406, piniongear 401, intermediate gear 403, and spur gear 416, for example. Invarious embodiments, referring to FIG. 84, the reversing drive canfurther include gear portion 158 extending from firing trigger 460 whichcan be configured such that, when firing trigger 460 is rotated aboutpin 161, similar to the above, gear portion 158 can rotate trigger gear496 about an axis defined by return pin 498. In at least one embodiment,gear portion 158 and trigger gear 496 can include teeth and/or recesseswhich can be configured to cooperate and transmit rotational motiontherebetween.

Referring to FIG. 77, also similar to the above, trigger gear 496 andreturn pin 498 can be configured such that they can be selectivelyengaged and disengaged with one another. In at least one suchembodiment, trigger gear 496 can be operably disengaged with return pin498 when firing member 466 is advanced by the firing drive. Statedanother way, trigger gear 496 can be configured such that it does nottransmit, or at least substantially transmit, rotational motion toreturn pin 498 when firing member 466 is being advanced by the firingdrive as described above. Furthermore, in at least one such embodiment,referring to FIGS. 77 and 79, return pin 498 can include key 499extending therefrom wherein key 499 can be held out of operativeengagement with D-shaped cavity 497 in trigger gear 496 until thereversing drive is operatively engaged with firing member 466 asdescribed in greater detail below. In order to hold key 499 out ofoperative engagement with trigger gear 496, referring to FIG. 84, returnpin 498 can include end 498 a which can be displaced, and/or held inposition, by return carriage 494 such that key 499 is positioned outsideof D-shaped cavity 497.

Before trigger gear 496 and return pin 498 are operatively engaged asmentioned above, pinion gear 401 of the reversing drive, referring toFIG. 71, can be operatively engaged with rack portion 405 of firingmember 466 such that, when firing member 466 is advanced distally by thefiring drive as described above, rack portion 405 can rotate pinion gear401 about an axis defined by axle 407. In various embodiments, rack 405can include a plurality of teeth and/or grooves which can be configuredto convert translational movement of firing member 466 into rotationalmovement of pinion gear 401. In various embodiments, intermediate gear403 can be mounted to or integrally formed with pinion gear 401 suchthat the translation of firing member 466 can rotate intermediate gear403 as well. In at least one embodiment, intermediate gear 403 and keygear 406 can include teeth and/or recesses which can be configured tocooperate and transmit rotational motion therebetween. Similarly, spurgear 416 can include teeth and/or recesses which can be configured tocooperate with the teeth and/or recesses of key gear 406 and transmitrotational motion therebetween. Thus, in view of the above, theadvancement of firing member 466 can rotate gears 401, 403, 406, and 416of the gear train.

In at least one embodiment, referring to FIGS. 71 and 84, spur gear 416can be mounted to or integrally-formed with indicator gear 492 suchthat, when spur gear 416 is rotated by key gear 406 as outlined above,indicator gear 492 can be rotated by spur gear 416. Thus, in at leastone such embodiment, the forward advancement of firing member 466 canrotate indicator gear 492 about an axis defined by aperture 407. Invarious embodiments, indicator gear 492 can include at least oneindicium thereon, such as letters, numbers, and/or any other suitablesymbols, for example, for displaying the number of times that firingtrigger 460 has been actuated, for example. In at least one suchembodiment, the housing of the surgical instrument can include a windowor aperture therein wherein a numeral “1”, for example, on indicatorgear 492 can be aligned with the window after a first actuation offiring trigger 460. Similarly, a numeral “2”, for example, on indicatorgear 492 can be aligned with the window after a second actuation offiring trigger and, correspondingly, a numeral “3”, for example, can bealigned with the window after a third actuation. Alternatively, in atleast one embodiment, indicator gear 492 can include indicia thereonwhich can correspond to the number of remaining actuations which arenecessary to fully advance firing member 466, the cutting member, and/orthe staple driver relative to the end effector.

After firing member 466 has been fully advanced relative to the endeffector, or at least suitably advanced, return carriage 494 can berotated downwardly, referring to FIGS. 76 and 82, in order to operablycouple the reversing drive, firing trigger 460, and firing member 466.In various embodiments, return carriage 494 can be rotated about pin 494a such that return carriage 494 no longer contacts, or at leastsubstantially contacts, return pin 498. Thereafter, referring to FIGS.77 and 78, spring 400 can slide or displace return pin 498 towardtrigger gear 496 and position at least a portion of key 499 withincavity 497. In at least one such embodiment, referring to FIG. 78,spring 400 can be positioned intermediate frame 484 and key 499 ofreturn pin 498 such that, when return carriage 494 no longer contactsend 498 a, spring 400 can expand and displace key 499 into cavity 497.In various embodiments, referring to FIG. 80, return carriage 494 canalso operably disengage the firing drive from firing member 466 whenreturn carriage 494 is rotated downwardly as described above. Moreparticularly, referring to FIG. 81, return carriage 494 can contact end220 of firing pin 172 such that firing pin 172 can be slid toward pawl170 and, as also described above, firing pin 172 can include key 222extending therefrom which can engage recess 173 in pawl 170 to preventpawl 170 from being pivoted upwardly to engage firing member 466. Thus,when pawl 170 is prevented from operably engaging firing member 466, thefiring drive may no longer engage firing member 466 and the reversingdrive can retract firing member 466 without interference from the firingdrive.

Further to the above, in various embodiments, return carriage 494 can berotated downwardly manually by a surgeon or by another clinician, forexample. In various embodiments, referring generally to FIGS. 68 and 82,the surgeon can apply a force to button portion 495 such that returncarriage 494 can be pivoted downwardly about an axis defined by pin 494a. Such a force can be applied after a predetermined amount ofactuations of the firing trigger although, in various embodiments, sucha force can be applied before the predetermined amount of actuations ofthe firing trigger is reached. In addition to or in lieu of the above,at least one of the gears of the reversing mechanism can be configuredto contact return carriage 494 after a predetermined number ofactuations of firing trigger 460. In various embodiments, referring toFIG. 76, indicator gear 492 can include cam 402 which can be configuredto contact a portion of return carriage 494 and apply a force theretoupon the third actuation of firing trigger 460. In at least one suchembodiment, the advancement of firing member 466 can rotate indicatorgear 492 a predetermined amount upon each actuation of trigger 460 suchthat cam 402 can contact carriage 494 upon the third, or final, strokeof trigger 460 which advances firing member 466. In effect, indicatorgear 492, or any other suitable gear of the reversing mechanism, can beconfigured to be rotated a predetermined amount before switching thesurgical instrument from an ‘advancing’ operating mode to a ‘reversing’operating mode.

Once return pin 498 has been operably engaged with trigger gear 496 andfiring pin 172 has been engaged with pawl 170 in order to prevent pawl170 from operably engaging firing member 466 as described above, firingtrigger 460 can be actuated once again in order to retract firing member466. In at least one such embodiment, the subsequent actuation of firingtrigger 466 can rotate trigger gear 492 and, owing to the operativeengagement between trigger gear 492 and return pin 498, trigger gear 492can rotate key gear 406. More particularly, referring to FIGS. 71, 77,and 78, return pin key 499 can be operatively engaged with drive surface410 of trigger gear 492 in addition to a sidewall of cavity 406 a withinkey gear 406 such that the rotation of trigger gear 496 is transmittedto key gear 406 via return pin 498. In various embodiments, referringagain to FIG. 71, the rotation of key gear 406 can rotate intermediategear 403 and pinion gear 401 in order to drive, or retract, firingmember 466 proximally. In effect, when trigger 460 is operably engagedwith the reversing drive, pinion gear 401 can be rotated in a directionwhich is opposite the direction in which it is rotated when firingtrigger 460 is operably engaged with the firing drive. In variousembodiments, the size, or pitch radius, of gears 401, 403, 406, 492, 496and gear portion 158 of trigger gear 460, for example, can be selectedsuch that firing member 466 can be returned by one actuation of trigger460, although other embodiments are envisioned in which more or lessthan one actuation of trigger 460 can be utilized.

After firing member 466 has been retracted, return carriage 494 can bepivoted upwardly into it its unactuated position in order to reset thesurgical instrument. In various embodiments, referring to FIGS. 85 and86, the surgeon or clinician can apply a force to button portion 452 oftrigger lock 448 such that trigger lock 448 can rotate upwardly and abutreturn carriage 494. In such circumstances, trigger lock 448 can rotatereturn carriage 494 upwardly as well and position carriage 494 in itsunactuated position. In doing so, return carriage 494 can engage end 221of firing pin 172 in order to slide firing pin 172 away from pawl 170and disengage key 222 from recess 173 in pawl 170 thereby allowing pawl170 to re-engage firing member 466 upon a subsequent actuation of firingtrigger 460. Return carriage 494 can also re-engage end 498 a of returnpin 498 when it is rotated upwardly so as to slide key 499 away fromtrigger gear 496, thereby operably disengaging return pin 498 fromtrigger gear 496 and, correspondingly, operably disengaging thereversing drive from firing member 466. Thereafter, the spent staplecartridge can be detached from the surgical instrument and replaced witha new staple cartridge such that the surgical instrument can be usedonce again.

In various alternative embodiments, a surgical instrument can include aclutch configured to operably engage and disengage a reversing drivewith a firing member. In at least one embodiment, referring to FIGS.87-94, surgical instrument 500, similar to surgical instrument 400, caninclude firing trigger 560 which can be configured to drive a firing pinand a pawl of a firing drive, for example, so as to advance firingmember 566, a cutting member, and/or staple driver relative to an endeffector. In various embodiments, also similar to the above, thesurgical instrument can further include a reversing drive comprisingpinion gear 501, intermediate gear 503, key gear 506, and spur gear 516.In at least one such embodiment, owing to the operative engagementbetween rack portion 505 of firing member 496 and pinion gear 501, theadvancement of firing member 466 can rotate gears 501, 503, 506 and 516as described in greater detail below. In various embodiments, return, orkey, pin 598 can be mounted to or integrally formed with key gear 506such that rotational motion is transmitted therebetween. In at least onesuch embodiment, referring to FIG. 89, at least a portion of return pin598 can include a non-circular cross-section including flat portion 598b, for example, which can, referring to FIG. 92, be slidingly receivedwithin a correspondingly-shaped aperture 506 b in key gear 506. Alsosimilar to the above, firing trigger 560 can include gear portion 558which can be operatively engaged with trigger gear 596 such that gearportion 558 can rotate trigger gear 596 about an axis defined by key pin598, as described in greater detail below.

In use, upon the first actuation of firing trigger 560, firing trigger560 can, similar to the above, rotate trigger gear 596 about key pin 598without directly transmitting rotational movement to key pin 598 viatrigger gear 596. Referring to FIG. 88, the first actuation of firingtrigger 560 can rotate trigger gear 596 in a direction indicated byarrow “A”, i.e., clockwise for the purposes of this discussion. Alsoupon the first actuation of firing trigger 560, firing member 566 canrotate pinion gear 501 and intermediate gear 503 in a directionindicated by arrow “B”, key gear 506 in a direction indicated by arrow“C”, and spur gear 516 and indicator gear 592 in a direction indicatedby arrow “D”. In various embodiments, as illustrated in FIG. 88, triggergear 596 and key gear 506 can be rotated in opposite directions duringthe first actuation of trigger 560 and may not operably engaged witheach other until after the first actuation of trigger 560 as describedfurther below. When trigger 560 is released or returned to itsunactuated position after its first actuation, the pawl of the firingdrive, for example, can be disengaged from the firing member 566 suchthat pinion gear 501 and key gear 506, for example, are not rotated, orat least substantially rotated, when trigger 560 is returned to itsstarting, or unactuated, position. Trigger gear 596, however, can berotated by firing trigger 560 when trigger 560 is returned to itsunactuated position and, as a result, trigger gear 596 can be rotatedrelative to key gear 506 as illustrated in FIG. 89. As trigger 560 isreturned to its unactuated position, as described above, inclinedsurface 509 of trigger gear 596 can contact clutch dog 599 of key pin598 and displace key pin 598 away from trigger gear 596 as illustratedin FIG. 90. Thereafter, trigger gear 596 can be further rotated byfiring trigger 560 until inclined surface 509 has entirely passed byclutch dog 599 and spring 500 can bias clutch dog 599 into a positionbehind drive surface 510 as illustrated in FIG. 91. At such point,firing trigger 560 may be in its unactuated position.

Upon a second actuation of firing trigger 560, the pawl of the firingdrive can remain disengaged from firing member 566 although the secondactuation of firing trigger 560 can once again rotate trigger gear 596in a direction indicated by arrow A, referring to FIG. 92. Owing to theposition of dog 599 behind drive surface 510 of trigger gear 596, therotation of trigger gear 596 can cause key pin 598 and key gear 506 torotate in a clockwise direction indicated by arrow A as well, i.e., in adirection opposite of arrow C. Correspondingly, key gear 506 can rotatepinion gear 501 and intermediate gear 503 in a direction indicated byarrow E, i.e., a direction opposite of arrow B, and also rotateindicator gear 592 in a direction indicated by arrow F, i.e., adirection opposite of arrow D. Owing to the rotation of pinion gear 501in an opposite direction during the second actuation of trigger 560,pinion gear 501 can retract firing member 566 relative to the endeffector and reposition, or at least substantially reposition, firingmember 566 in its starting, or unactuated, position. Thereafter, firingtrigger 566 can be released and returned to its unactuated position. Insuch circumstances, drive surface 510 of trigger gear 596 can be rotatedaway from clutch dog 599 and, whereas the pawl of the firing drive canstill be operatively disengaged from firing member 566, key pin 598 andkey gear 596 can remain in position. In order to reset the surgicalinstrument, the pawl of the firing drive can be released such that itcan re-engage firing member 566 upon the next actuation of trigger 560.In such embodiments, the spent staple cartridge can be replaced suchthat the surgical instrument can be used once again.

In various embodiments, referring to FIG. 94, surgical instrument 500can further include trigger lock 548 which, similar to trigger lock 148described above, can be utilized to hold a closure trigger in position.In at least one embodiment, trigger lock 548 can be rotated betweenactuated and unactuated positions to lock and unlock, respectively, aclosure trigger such as closure trigger 428 (FIG. 68), for example. Inat least one such embodiment, when trigger lock 548 is in its unactuatedposition, portion 548 a of trigger lock 548 can be positioned withinrecess 592 a of indicator 592 to prevent, or at least substantiallyprevent, the gear train and firing member 566 from being unintentionallymotivated. Stated another way, when portion 548 a is positioned withinrecess 592 a, the firing and reversing drives described above can berendered substantially inoperative and, as a result, firing member 566cannot be substantially moved. When trigger lock 548 is moved into itsactuated position to hold or lock the closure trigger in place, portion548 a of trigger lock 548 can be moved, or rotated, out of recess 592 asuch that the firing and reversing drives described above can beoperated.

In various alternative embodiments, a surgical instrument can include aratchet configured to operably engage and disengage a reversing drivewith a firing member. In at least one embodiment, referring to FIGS.95-100, surgical instrument 600 can include firing trigger 660 which canbe configured to drive a firing pin and a pawl of a firing drive, forexample, so as to advance firing member 666, a cutting member, and/orstaple driver relative to an end effector, similar to the above. Invarious embodiments, also similar to the above, the surgical instrumentcan further include a reversing mechanism comprising pinion gear 601,key gear 606, and spur gear 616 where the advancement of firing member666 can rotate gears 601, 606 and 616 owing to the operative engagementbetween rack portion 605 of firing member 696 and pinion gear 601. Invarious embodiments, return, or key, pin 698 can be mounted to orintegrally formed with key gear 606 such that rotational motion can betransmitted therebetween. Also similar to the above, firing trigger 660can include gear portion 658 which can be operatively engaged withtrigger gear 696 such that gear portion 658 can rotate trigger gear 696about an axis defined by key pin 698.

In use, upon the first actuation of firing trigger 660, firing trigger660 can rotate trigger gear 696 about key pin 698 without directlytransmitting rotational movement to key pin 698 and key gear 606. Moreparticularly, referring to FIG. 97, trigger gear 696 can includeaperture 696 a which can be configured such that there is a clearancefit between key pin 698 and the sidewalls of aperture 696 a and, as aresult, key pin 698 can rotate therein. Furthermore, referring to FIG.96, key gear 606 can include ratchet face 606 c and trigger gear 696 caninclude ratchet face 696 c which, when firing member 666 is beingadvanced by the firing drive, can be operably disengaged, or separated,from one another such that rotational movement is also not transmittedtherebetween. After firing member 666 has been sufficiently advanced,similar to the above, return carriage 694 can be rotated downwardlyabout pin 694 a, for example, such that return carriage 694, referringto FIG. 99, can be disengaged from end 698 a of return pin 698. In suchcircumstances, as described in greater detail below, return pin 698 canbe operatively engaged with trigger gear 696 and firing member 666 canbe retracted.

In various embodiments, further to the above, return carriage 694 can bemanually moved between its unactuated position illustrated in FIG. 95 toits actuated position illustrated in FIG. 99, similar to return carriage494. In addition to or in lieu of the above, at least one of the gearsin the gear train, such as indicator gear 692, for example, can includea cam, such as cam 602, for example, which can contact return carriage694 and rotate it downwardly after a predetermined amount of actuationsof firing trigger 660. Thereafter, in either event, key gear 606 can beslid toward trigger gear 696 by spring 600. More particularly, referringto FIG. 100, spring 600, which can be positioned, or compressed,intermediate key gear 606 and a frame of the surgical instrument, forexample, such that, once return carriage 694 has been disengaged fromend 698 a of return pin 698, spring 600 can expand to slide key gear 606toward trigger gear 696. Furthermore, in at least one embodiment, returnpin 698 can be mounted to or integrally formed with key gear 606 suchthat return pin 698 can be slid toward trigger gear 696 with key gear606. In at least one embodiment, referring to FIG. 97, return pin 698can include collar 698 b in which key gear 606 can abut and push returnpin 698 toward trigger gear 696.

In various embodiments, as a result of the above, ratchet faces 606 cand 696 c can be positioned against one another by spring 600 whenreturn carriage 694 is rotated downwardly into its actuated position asillustrated in FIG. 100. In at least one embodiment, referring to FIG.97, ratchet faces 606 c and 696 c can each include teeth extendingtherefrom which can cooperate to transmit rotational movementtherebetween. In use, upon a subsequent actuation of firing trigger 660,firing trigger 660 can rotate trigger gear 696, and key gear 606, in aclockwise direction indicated by arrow A, referring to FIG. 99, whereinkey gear 606 can rotate pinion gear 601 in a direction indicated byarrow E. As a result of the operative engagement between pinion gear 601and rack portion 605 of firing member 666, for example, pinion gear 601can retract firing member 666, the cutting member, and/or the stapledriver relative to the end effector, similar to the above. In at leastone embodiment, gears 601, 606, and 696 and gear portion 658 can beconfigured such that firing member 666 can be fully retracted with oneactuation of trigger 460.

Thereafter, firing trigger 460 can be released and/or returned to itsunactuated position. In at least one such embodiment, ratchet faces 606c and 696 c can include beveled surfaces which can allow ratchet faces606 c and 696 c to rotate relative thereto when trigger 660 is returnedto its unactuated position. In such circumstances, trigger gear 696 canbe rotated in a counterclockwise direction, i.e., in a directionopposite of that indicated by arrow A. In at least one embodiment,ratchet faces 606 c and 696 c can rotate relative to each other eventhough the ratchet faces are in contact with one another. Thereafter,return carriage 694 can be rotated upwardly such that it can contact end698 a of return pin 698 and slide return pin 698 and key gear 606 awayfrom trigger gear 696. In such circumstances, as a result, ratchet face606 c can be disengaged from ratchet face 696 c such that they are nolonger operably engaged with one another. In at least one suchembodiment, return carriage 694 can apply a force to end 698 a of returnpin 698, wherein the force can be transmitted to key gear 606 via collar698 b in order to displace key gear 606 away from trigger gear 696.

As described above, surgical instruments in accordance with the presentinvention can include a firing drive having a pawl which can beconfigured to advance a firing member relative to an end effector. Invarious embodiments, as described above, pawl 170 can be pivotedupwardly to engage a recess 467 in firing member 466, for example, andadvance firing member 466 distally. Thereafter, referring once again toFIGS. 101 and 102, pawl 170 can be pivoted downwardly and retractedproximally relative to firing member 466 so as to reposition pawl 170such that pawl 170 can be pivoted upwardly once again to engage anotherrecess 467 and further advance firing member 466. In variouscircumstances, though, pawl 170 may not be able to engage a recess 467when it is pivoted upwardly as illustrated in FIG. 103. Suchcircumstances may arise when firing member 466, for example, isunintentionally moved by forces or energy transmitted through and/orstored within the various mechanisms of the surgical instrument. If thepawl is unable to re-engage the firing member, the surgical instrumentmay be rendered inoperable and, as a result, the surgical instrument mayhave to be manually reset. In order to ameliorate this condition,surgical instruments in accordance with various embodiments of thepresent invention can include an anti-backup mechanism which can retain,or at least substantially retain, the firing member in position.

In various embodiments, referring to FIG. 104, an anti-backup mechanismcan be configured to hold at least a portion of a firing drive and/orreversing drive in position while pawl 170 is retracted relative tofiring member 466, for example. In at least one embodiment, ananti-backup mechanism can include indexing mechanism, or plate, 711which can be configured to permit return pin 798 to rotate in acounter-clockwise direction indicated by arrow B when firing member 466is advanced, as described above, yet prohibit, or at least substantiallyprohibit, return pin 798 from rotating in a clockwise direction, i.e.,in a direction opposite of arrow B. In effect, as return pin 798 isrotatably engaged with key gear 406, and key gear 406 is operablyengaged with firing member 466 via intermediate gear 403 and pinion gear401, indexing mechanism 711 can also prevent, or at least substantiallyprevent, firing member 466 from being retracted proximally. Furthermore,as described in greater detail below, indexing mechanism 711 can alsoinhibit firing member 466 from being unintentionally advanced distallyas well.

In order to prevent return pin 798 from unintentionally rotating asoutlined above, indexing element 711 can include one or more recessesand/or apertures therein for holding or retaining return pin 798 inposition. In various embodiments, referring to FIGS. 104, 107, and 111,indexing mechanism 711 can comprise a leaf spring including clip end 711a which can be retained within recess 784 a of frame 784 such thatindexing mechanism 711 can flex and/or rotate relative to fulcrum 784 bof frame 784. In at least one embodiment, referring to FIGS. 105 and106, return pin 798 can include key 799 extending therefrom wherein key799 can be configured to engage indexing mechanism 711. Moreparticularly, in at least one such embodiment, indexing mechanism 711can include a plurality of recesses, or apertures, 713 a-d, referring toFIGS. 107 and 108, which can each be configured to retain projection 799a extending from key 799 therein and thereby hold return pin 798 inposition as described in greater detail below.

In use, an end effector of the surgical instrument can be closed ontothe soft tissue of a patient, for example and, thereafter, as outlinedabove, a firing member of the surgical instrument can be advanced by afiring drive. Prior to the advancement of the firing member, projection799 a of return pin 798 can be received within first aperture 713 a ofindexing element 711 as illustrated in FIG. 110 a. In variousembodiments, referring to FIGS. 106 and 109, key 799 can further includeinclined or beveled surface 799 b which can be configured such that,when return pin 798 is rotated in a direction indicated by arrow B byfiring member 466, pinion gear 401, intermediate gear 403, and key gear406 upon the first actuation of trigger 460, beveled surface 799 b cancontact the edge of aperture 713 a and deflect and/or rotate indexingmechanism 711 downwardly as illustrated in FIG. 110 b. Notably, acertain amount of force may be required to deflect and/or rotateindexing mechanism 711 and, as a result, the possibility of return pin798 being unintentionally displaced from recesses 713 can be reduced.More particularly, absent a large pulling force applied to firing member766, for example, the recesses in the indexing element may be able tohold key 799 of return pin 798 therein and, correspondingly, thepossibility that firing member 466 may be unintentionally advanced canalso be reduced.

By the end of the first actuation of firing trigger 460, key 799 can bepositioned within second aperture 713 b of indexing mechanism 711 asillustrated in FIG. 110 c. In such a position, key 799 can be preventedfrom moving backward into aperture 713 a owing to stop surface 799 c.More particularly, referring to FIG. 108, key 799 can further includestop surface 799 c which can be configured to abut the perimeter ofaperture 713 b, for example, and, owing to the configuration of stopsurface 799 c, aperture 713 b and stop surface 799 c can be configuredto prevent key 799 from deflecting or rotating indexing mechanism 711downwardly within recess 715 (FIG. 111) and allowing return pin 798 tobe rotated in a direction opposite of arrow B. In at least one suchembodiment, stop surface 799 c and the perimeter of aperture 713 b caninclude surfaces which are parallel to one another. In other variousembodiments, the abutting surfaces can include at least partiallybeveled portions which can be configured such that, when stop surface799 c is forced against the edge of aperture 713 b, key 799 can befurther drawn into aperture 713 b as opposed to being lifted out of thesame. In either event, owing to the operative relationship betweenreturn pin 798, the gears of the gear train, and firing member 466 asdescribed above, firing member 466 can be prevented, or at leastsubstantially prevented, from unintentionally retracting proximally byindexing member 711. In such embodiments, as a result, the possibilitythat pawl 170 may be misaligned relative to the recesses 467 withinfiring member 466 when pawl 170 is retracted relative to firing member466, for example, can be reduced.

Upon a second actuation of firing trigger 460, firing member 466 canonce again rotate gears 401, 403, and 406 such that return pin 798 isrotated in a direction indicated by arrow B. In various embodiments, asa result, beveled surface 799 b can contact the edge of second aperture713 b and deflect and/or rotate indexing mechanism 711 downwardly asillustrated in FIG. 110 d. By the end of the second actuation of firingtrigger 460, key 799 can be positioned within third aperture 713 c ofindexing mechanism 711 as illustrated in FIG. 110 e. In such a position,key 799 can be prevented from moving backward into second aperture 713 bowing to stop surface 799 c, similar to the above. Furthermore, upon athird actuation of firing trigger 460, firing member 466 can once againrotate return pin 798 in a direction indicated by arrow B and, as aresult, beveled surface 799 b can contact the edge of third aperture 713c and deflect and/or rotate indexing mechanism 711 downwardly asillustrated in FIG. 110 f. By the end of the third actuation of firingtrigger 460, key 799 can be positioned within fourth aperture 713 d ofindexing mechanism 711 as illustrated in FIG. 110 g. In such a position,similar to the above, key 799 can be prevented from moving backward intothird aperture 713 c owing to stop surface 799 c.

At such point, in order to operably engage the reversing drive with thefiring member, similar to the above, return pin 798 and key 799 can bemoved toward trigger gear 496 in order to operably engage key gear 406with trigger gear 496. In various embodiments, as a result, projection799 a can be moved away from indexing member 711 and out of fourthaperture 713 d. Thereafter, upon the return stroke of firing trigger460, firing member 466 can be retracted and return pin 798 can berotated in a clockwise direction, i.e., in a direction opposite arrow B.At such point, firing member 466 and pawl 170 will have both beenreturned to their starting positions, return pin 798 will have beenrotated such that it is realigned with first aperture 713 a, and returnpin 798 can be disengaged from trigger gear 496 such that key 499 isslid into engagement with first aperture 713 a. Thereafter, as a result,the surgical instrument can be used once again.

In various alternative embodiments, referring to FIGS. 112 and 113, ananti-backup mechanism can include indexing element, or plate, 811 whichcan be rotatably mounted within recess 884 a of frame 884 such thathinge end 811 a can be rotatably mounted to pin portion 884 b. In atleast one embodiment, similar to the above, indexing element 811 can berotated and/or deflected relative to pin 811 b. In various embodiments,the anti-backup mechanism can further include at least one springelement, or return spring, 811 b within recess 815 which can beconfigured to bias indexing member 811 into the position illustrated inFIGS. 112 and 113. Similarly, return spring 811 b can be furtherconfigured to restore indexing element to such a position after it hasbeen deflected by key 799 as outlined above. In various embodiments, theat least one return spring can be positioned intermediate indexingelement 811 and a sidewall of recess 815, for example. In variousalternative embodiments, referring to FIG. 114, an anti-backup mechanismcan include indexing element 911 which, similar to the above, can bemounted within recess 984 a of frame 984. In at least one suchembodiment, frame 984 can further include mounting projections 984 bwhich can be configured to be press-fit within apertures 911 a inindexing element 911 such that indexing element 911 can be flexed and/orrotated relative to frame 984.

In various alternative embodiments, an anti-backup mechanism inaccordance with at least one embodiment of the present invention caninclude a ratchet mechanism for preventing, or at least limiting,undesirable movement of the firing member and/or gear train. In variousembodiments, referring to FIGS. 115-118, the ratchet mechanism caninclude a pawl which can be configured to allow the gears of the geartrain, such as indicator gear 492 and spur gear 416, for example, torotate in a first direction when they are driven by the firing member,such as firing member 466, for example, yet prohibit, or at least limit,the gears from rotating in an opposite direction when the pawl of thefiring drive, such as pawl 170, for example, is retracted relative tothe firing member. In at least one embodiment, referring to FIG. 116,the ratchet mechanism can include leaf spring, or pawl, 1011 which canlimit the rotation of spur gear 416 as described in greater detailbelow.

Further to the above, when firing member 466, for example, is advancedby firing trigger 460, for example, firing member 466 can rotate spurgear 416 in a direction indicated by arrow D (FIG. 116) owing to theoperative engagement of pinion gear 401, intermediate gear 403, key gear406, and spur gear 416 as described above. When spur gear 416 is rotatedin direction D, in at least one embodiment, gear teeth 416 a of gear 416can be configured to contact and deflect pawl 1011 such that gear teeth416 a can pass thereby. However, in the event that firing member 466 isunintentionally retracted and/or spur gear 416 is rotated in a directionindicated by arrow H, pawl 1011 can be configured such that at least aportion thereof can be positioned intermediate two adjacent gear teeth416 a and prevent, or at least limit, spur gear 416 from rotating indirection H. In various embodiments, referring to FIG. 116, at least aportion of pawl 1011 can be wedged between gear teeth 416 a or ‘bite’into gear 416 such that gear 416 cannot substantially rotate indirection H, at least not until the reversing drive of the surgicalinstrument is operably engaged with the firing member as described ingreater detail below.

In various embodiments, the surgical instrument can include a returncarriage which can be moved between an unactuated position asillustrated in FIGS. 115 and 116 and an actuated position as illustratedin FIGS. 117 and 118 to place the surgical instrument in its reversingor retracting mode of operation. Similar to return carriage 494, in atleast one embodiment, return carriage 1094 can be rotated relative toframe 484 about pin 1094 a. In various embodiments, referring to FIG.118, pawl 1011 can be mounted to return carriage 1094 such that, whenreturn carriage 1094 is rotated downwardly into its actuated position,pawl 1011 can be moved out of operative engagement with spur gear 416.In such circumstances, spur gear 416 can be permitted to rotate in adirection indicated by arrow H when the surgical instrument is placed inits reversing mode. When spur gear 416 is permitted to rotate indirection H, the gear train can be permitted to rotate withoutinterference, or at least substantial interference, from the anti-backupmechanism such that the firing member can be retracted as outlinedabove. After the firing member has been sufficiently retracted, returncarriage 1094 can be rotated upwardly into its unactuated position andpawl 1011 can be operably re-engaged with spur gear 416.

In various circumstances, a reversing drive of a surgical instrument maybe prevented from being properly engaged with a firing member of thesurgical instrument. In at least one embodiment, the return carriage ofa reversing drive, such as return carriages 494 and 1094, for example,may not be able to properly contact and motivate firing pin 172 and/orreturn pin 498, for example. More particularly, the return carriage mayfail to properly displace firing pin 172 and/or return pin 498 such thatkey gear 406 is operably engaged with trigger 496 and, furthermore, suchthat pawl 170 is prevented from operably engaging firing member 466. Invarious embodiments, as outlined above, a return carriage can include abutton portion which can be configured to manually rotate the returncarriage downwardly when a force is applied thereto. In variouscircumstances, however, this force may have insufficient leverage tomove the return carriage, especially if the return carriage and/or oneof pins 172 and 498 is stuck in position, for example.

In various embodiments of the present invention, a surgical instrumentcan include a switch which can be better configured to manually engagethe reversing drive of the surgical instrument with the firing member.In at least one embodiment, referring to FIG. 119, the switch caninclude first and second portions, wherein first portion 1194 can bemovably connected relative to frame 1184, for example, and whereinsecond portion 1118 can also be movably connected relative to frame 1184as well. In various embodiments, first switch portion 1194 can bepivotably connected to frame 1184 such that, when first switch portion1194 is pivoted downwardly by a cam, similar to cam 402, for example,first portion 1194 can be configured to disengage return pin 498 andallow key portion 499 of return pin 498 to engage trigger gear 496 asdescribed above. In various embodiments, although not illustrated inFIG. 119, return carriage 1194 can include arm 1194 d extendingtherefrom which can be moved away from end 498 a of return pin 498 suchthat a spring, for example, can bias return pin 498 into operativeengagement with trigger gear 496.

In addition to the above, first switch portion 1194, when pivoteddownwardly, can be configured to contact return pin 172 and operablyengage key 222 of return pin 172 with pawl 170 such that pawl 170 cannotbe pivoted upwardly, as also described above. In effect, in at least onesuch embodiment, first switch portion 1194 can comprise a cam which canbe actuated to operably disengage the firing drive from, and operablyengage the reversing drive with, the firing member. In variouscircumstances, only the operation of first portion 1194 may be needed inorder to switch the surgical instrument between its advancing andreversing operating modes. In the event, however, that the cam of thereversing drive, such as cam 402, for example, cannot properly position,or actuate, first switch portion 1194, second portion 1118 of the switchmay be utilized to actuate first switch portion 1194 as described ingreater detail below.

Further to the above, second switch portion 1118 can be actuated inorder to actuate first switch portion 1194. In various embodiments,referring again to FIG. 119, second switch portion 1118 can includehandle 1118 b which can be configured to be grasped by a surgeon, forexample, such that the surgeon can apply a force thereto and rotateswitch portion 1118 about pivot 1118 a. In at least one embodiment,second switch portion 1118 can be configured to contact first switchportion 1184 and move first portion 1184 between its unactuated positionillustrated in FIG. 119 and its actuated position as described above. Invarious embodiments, in effect, second switch portion 1118 can comprisea cam which can contact first portion 1194 and drive first portion 1194downwardly such that first portion 1194 contacts firing pin 172 andreturn pin 498. In at least one such embodiment, referring to FIG. 119,second switch portion 1118 can include contact surface 1118 c which canbe configured to contact surface 1194 c of first switch portion 1194. Invarious embodiments, contact surface 1118 c can be positioned directlyabove contact surface 1194 c such that surfaces 1118 c and 1194 c can bealigned and the possibility of second switch portion 1118 not contactingfirst switch portion 1194 can be reduced.

In various embodiments, further to the above, contact surfaces 1118 cand 1194 c can be positioned and arranged such that a force, F₂, appliedto handle 1198 b has sufficient mechanical advantage to move firstswitch portion 1194 into its actuated position. In at least oneembodiment, handle force F₂ can be transmitted through the body ofsecond switch portion 1118 and to first switch portion 1194 via contactsurfaces 1118 c and 1194 c as transmission force F₃. Notably, in variousembodiments, transmission force F₃ can be different than handle force F₂Further to this point, referring to FIG. 119, the torques associatedwith handle force F₂ and transmission force F₃ in order to initiallymove first switch portion 1194 can be substantially the same, i.e., theproduct of distance Da and force F₂ can substantially equal the productof distance Db and force F₃, wherein distance Da can represent thedistance between pivot 1118 a and the application of force F₂, andwherein distance Db can represent the distance between pivot 1118 a andthe transmission of force F₃. Thus, when distance Da is smaller thandistance Db, as illustrated in FIG. 119, force F₂ can be larger thanforce F₃. Accordingly, in order for force F₃ to be substantially equalto force F₂, handle 1118 b would have to be positioned substantiallyabove surfaces 1118 c and 1194 c when force F₂ is applied to handle 1118b.

In various embodiments, further to the above, transmission force F₃ canbe transmitted through the body of first switch portion 1194 to firingpin 172 as displacement force F₁. Similar to the above, displacementforce F₁ can be different than transmission force F₃. Further to thispoint, referring again to FIG. 119, the torques associated withdisplacement force F₁ and transmission force F₃ in order to initiallydisplace firing pin 172 toward pawl 170, as outlined above, can besubstantially the same, i.e., the product of distance Dc and force F₁can substantially equal the product of distance Dd and force F₃, whereindistance Dc can represent the distance between pivot 1194 a and theapplication of force F₃, and wherein distance Dd can represent thedistance between pivot 1194 a and the transmission of force F₃. Thus,when distance Dc is smaller than distance Dd, as illustrated in FIG.119, force F₁ can be larger than force F₃. In effect, the smallertransmission force F₃ can be utilized to apply a larger displacementforce F₁ to firing pin 172, depending on the selection of distances Da,Db, Dc, and Dd. In various embodiments, as a result, the first andsecond portions of the switch can be configured such that force F₂supplied by the surgeon, for example, can be sufficient to manuallyposition the first portion of the switch in its actuated position viathe second portion of the switch and thereby manipulate the surgicalinstrument from an advancing operating mode to a reversing operatingmode, as outlined further above. In order to return the surgicalinstrument to its advancing operating mode, first switch portion 1194,for example can be rotated upwardly such that second switch portion 1118can also rotated upwardly, thereby resetting the switch assembly.

In a further exemplary embodiment, referring to FIGS. 120-122, asurgical instrument can include a switch assembly comprising firstportion 1294 which can be pivotably mounted to frame 1284 about pin 1294a and, in addition, a second portion 1218 which can be pivotably mountedto frame 1284 about pivot 1218 a. Although the first and second switchportions can be pivotably mounted to frame 1284, the switch portions canbe pivotably mounted to any other suitable portion of the surgicalinstrument. In various embodiments, similar to the above, first switchportion 1294 can be operated to switch the surgical instrument betweenadvancing and reversing operated modes. In at least one embodiment,first switch portion 1294 can be rotated between its unactuated positionillustrated in FIG. 120 and its actuated position illustrated in FIG.121. Similar to the above, second switch portion 1218 can be moveddownwardly by a force applied to handle 1218 b in order to move firstportion 1294 downwardly into its actuated position.

In various embodiments, second switch portion 1218, for example, and thefiring trigger of the surgical instrument, such as firing trigger 460,for example, can be configured such that second portion 1218 can beprevented, or at least substantially prevented, from being rotateddownwardly unless the firing trigger is in its unactuated position. Byrequiring that the firing trigger be in its unactuated position beforeallowing the switch to be operated, first switch portion 1294 of thereversing mechanism may be properly aligned with the firing pin of thefiring drive, such as firing pin 172, for example, when first portion1294 is rotated downwardly. In various embodiments, the surgicalinstrument can be configured such that the firing pin is positionedwithin a predetermined range such that the firing pin can be contactedby first switch portion 1294 and slid into engagement with the pawl ofthe firing drive, such as pawl 170, for example.

In various embodiments, referring to FIG. 50, surgical instrument 100can include end effector 106 and elongate shaft assembly 104, where endeffector 106 and shaft assembly 104 can be pivotably connected byarticulation joint 114. As outlined above, articulation joint 114 canallow end effector 106 to be moved, or articulated, relative to shaftassembly 106 about axis 116. In various circumstances, a surgeon canarticulate end effector 106 to more easily access a surgical site withina patient's body. More particularly, a surgeon may insert end effector106 and shaft assembly 104 through a cannula at least partially insertedinto the patient's body and, once end effector 106 has passed throughthe cannula, end effector 106 can be pivoted, or articulated, in orderto position end effector 106 relative to soft tissue, for example, inthe surgical site that is to be stapled and/or incised. Once endeffector 106 has been positioned, the relative relationship between endeffector 106 and shaft assembly 104 can be fixed, or locked, by alocking mechanism as described in greater detail further below.

In at least one embodiment, referring to FIGS. 51 and 52, articulationjoint 114 can include end effector lock member 300 and pivot 302. Invarious embodiments, referring to FIGS. 53-56, end effector lock member300 can include connector portion 320 which can secure lock member 300to end effector 106 and, referring to FIG. 52, shaft assembly 104 caninclude pivot connector 342, where pivot connector 342 can include pivot302 extending therefrom. In various embodiments, lock member 300 caninclude aperture 301 which can be sized and configured to receive atleast a portion of pivot 302 therein. In at least one embodiment, pivot302 and aperture 301 can be configured such that end effector 106 canrotate freely about axis 116. In other various embodiments, pivot 302and aperture 301 can be configured such that friction between pivot 302and aperture 301 can resist, although permit, relative movement betweenend effector 106 and shaft assembly 104. Although not illustrated,articulation joint 114 can include more than one axis, or pivot, aboutwhich end effector 106 can be rotated.

In various embodiments, a surgeon can articulate end effector 106relative to shaft assembly 104 by pushing end effector 106 against acavity side wall surrounding a surgical site, for example, and applyinga force to shaft assembly 104 such that end effector 106 pivots aboutaxis 116. Thereafter, if the surgeon desires to re-center end effector106, i.e., orient end effector 106 and shaft assembly 104 along a line,the surgeon can place end effector 106 against a cavity side wall onceagain, for example, and a apply a force to shaft assembly 104 asdescribed above. In various embodiments, referring to FIGS. 51 and 52,surgical instrument 100 can include a re-centering mechanism which canautomatically re-center, or at least substantially re-center, endeffector 106 relative to shaft assembly 104. In various embodiments, endeffector lock member 300 can include centering surfaces 316 and elongateshaft assembly 104 can include centering shafts 328 and biasing members330, where biasing members 330 can be configured to bias centeringshafts 328 against centering surfaces 316. In at least one suchembodiment, centering surfaces 316 can be disposed on substantiallyopposite sides of axis 116 such that centering shafts 328 can apply asubstantially equal torque, or moment, to lock member 300 and, absent anadditional motivating force, hold end effector 106 in a substantiallycentered position. When end effector 106 is articulated by such amotivating force, as described above, lock member 300 can be configuredto displace one of centering shafts 328 proximally and compress thebiasing member 330 operably engaged therewith. More particularly, thebiasing member 330 can be positioned between a guide 331 and at leastone projection 329 extending from centering shaft 328 such that, whenprojection 329 is moved proximally by shaft 328, biasing member 330 iscompressed therebetween. After the motivating force is removed, thecompressed biasing member 330 can expand and rotate lock member 300 toits center position via centering shaft 328, or to a position where thetorque applied by biasing members 330 is substantially balanced.Although biasing member 330 is illustrated as a coil spring, biasingmember 330 can include any suitable elastic member.

In various embodiments, a locking mechanism can be used to hold endeffector 106 in its articulated position even after the motivating forcehas been removed. In at least one embodiment, referring to FIGS. 53-56,end effector lock member 300 can include a first portion having firstsurface 308, a second portion having second surface 304, teeth 312, andrecesses 314 defined between teeth 312 where, as described in greaterdetail further below, teeth 312 and recesses 314 can be configured to beoperably engaged with a shaft assembly locking member in order to fix,or lock, the relative relationship between end effector 106 and shaftassembly 104. In various embodiments, teeth 312 and recesses 314 can bepositioned intermediate first surface 308 and second surface 304. In atleast one embodiment, first surface 308 can extend from aperture 301 tofirst perimeter 310, and second surface 304 can extend from aperture 301to second perimeter 306. In various embodiments, first perimeter 310 candefine a first plane and second perimeter 306 can define a second planewhere teeth 312 and recesses 314 can be positioned intermediate thefirst and second planes. In embodiments where first perimeter 310 isdifferent than second perimeter 306, teeth 312 can extend at an angle,or bevel, therebetween. In various embodiments, a tooth 312 canintersect first perimeter 310 at a point further away from axis 116 thana point at which the tooth 312 intersects second perimeter 306. In atleast one embodiment, at least one of the teeth 312 can define a firstaxis 313 which can extend between first surface 308 and second surface304 in a direction which is not perpendicular to first surface 308and/or axis of rotation 116. In such embodiments, teeth 312 can slideover soft tissue, for example, which is positioned adjacent toarticulation joint 114. Stated another way, owing to the angled, orbeveled, surfaces of teeth 112, the probability of teeth 112 catchingon, or impinging upon, the soft tissue surrounding articulation joint114 when end effector 106 is articulated can be reduced. In at least oneembodiment, teeth 312 may not extend beyond first perimeter 310 suchthat, in the event that at least a portion of first perimeter 310 is incontact with soft tissue, for example, first perimeter 310 and teeth 312can, as above, easily slide relative to the soft tissue.

Further to the above, embodiments of the present invention can providesignificant advantages over previous surgical instruments. Moreparticularly, referring to FIG. 57, the articulation joints of previousend effectors have included lock members, such as lock member 299, forexample, which include teeth 298 that extend outwardly from theperimeter of the lock member. As a result, when the end effector isarticulated relative to the shaft assembly of the surgical instrument,teeth 298 can catch on, or impinge upon, the surrounding soft tissue andpotentially cause trauma thereto. In various circumstances, tissue canbe caught between adjacent teeth 298 such that, when the end effector isarticulated, the soft tissue can be pulled into the articulation jointand can be pinched by the relatively moving components of the joint. Inembodiments of the present invention in which the teeth of the lockmember are angled, or beveled, as outlined above and illustrated in FIG.58, the soft tissue can more easily flow over the teeth and reduce thepossibility that the soft tissue can be pulled into the articulationjoint.

As outlined above, referring to FIGS. 59-62, surgical instrument 100 canfurther include locking member 120 which can be slid relative to endeffector 106 and can be operably engaged with end effector 106 toprevent, or at least limit, relative movement between shaft assembly 104and end effector 106. In at least one embodiment, lock member 120 can beconfigured to engage at least one of teeth 312 such that end effector106 is prevented from moving relative to lock member 120. Moreparticularly, lock member 120 can include end portion 338 and shaftportion 340, where end portion 338 can include recess 336 which can beconfigured to receive a tooth 312 of lock member 300 in a close-fit, oreven interference-fit, relationship. In various alternative embodiments,locking portion 338 can be received within at least one of recesses 314in a close-fit, or interference-fit, relationship similar to the above.In either event, surgical instrument 100 can further include spring 126which can be configured to bias lock member 120 into engagement with endeffector lock member 300. In the event that recess 336 is not alignedwith a tooth 312, in at least one embodiment, the biasing force appliedto lock member 120 by spring 126 can cause lock member 120 to contactand rotate end effector lock member 300 about axis 116 until one ofteeth 312 is aligned with recess 336. In various embodiments, spring 126can comprise any suitable biasing member including a helical spring,leaf spring, or other biasing material.

In various alternative embodiments, referring to FIGS. 63-67, a surgicalinstrument can include end effector lock member 350 comprising aperture301, a first portion including first surface 358, a second portionincluding second surface 354 (FIG. 67), and connector portion 320. Endeffector lock member 350 can also comprise teeth 362 and recesses 364defined between teeth 362 where, in at least one embodiment, teeth 362and recesses 364 can be positioned intermediate first surface 358 andsecond surface 354. In various embodiments, referring to FIGS. 65-67,teeth 362 may not extend beyond first perimeter 357 of first surface 358and/or second perimeter 353 of second surface 354. In at least one suchembodiment, teeth 362 may be completely positioned, or contained,between first surface 358 and second surface 354. In at least onealternative embodiment, teeth 362 may partially extend from firstperimeter 357 and/or second perimeter 353. In various embodiments, firstperimeter 357 and second perimeter 353 can define an outer surfacetherebetween where recesses 364 can be defined in the outer surface. Asa result of the above-described features, end effector lock member 350can slide relative to soft tissue positioned adjacent to thearticulation joint without impinging on the soft tissue. In variousembodiments, teeth 362 may be blunted or rounded to further facilitatethe relative sliding described above. In at least one embodiment,referring to FIGS. 63-65, a locking mechanism can be configured toengage at least one of teeth 362 and recesses 364 and can include lockmember 382 comprising end portion 388 and shaft portion 390. In at leastone embodiment, similar to the above, end portion 388 can include recess394 which can be configured to engage at least one of teeth 362, forexample.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, the device can be reconditioned for reuse after at leastone use. Reconditioning can include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, the devicecan be disassembled, and any number of the particular pieces or parts ofthe device can be selectively replaced or removed in any combination.Upon cleaning and/or replacement of particular parts, the device can bereassembled for subsequent use either at a reconditioning facility, orby a surgical team immediately prior to a surgical procedure. Thoseskilled in the art will appreciate that reconditioning of a device canutilize a variety of techniques for disassembly, cleaning/replacement,and reassembly. Use of such techniques, and the resulting reconditioneddevice, are all within the scope of the present application.

Preferably, the invention described herein will be processed beforesurgery. First, a new or used instrument is obtained and if necessarycleaned. The instrument can then be sterilized. In one sterilizationtechnique, the instrument is placed in a closed and sealed container,such as a plastic or TYVEK bag. The container and instrument are thenplaced in a field of radiation that can penetrate the container, such asgamma radiation, x-rays, or high-energy electrons. The radiation killsbacteria on the instrument and in the container. The sterilizedinstrument can then be stored in the sterile container. The sealedcontainer keeps the instrument sterile until it is opened in the medicalfacility.

While this invention has been described as having exemplary designs, thepresent invention may be further modified within the spirit and scope ofthe disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains.

1. A surgical instrument, comprising: an end effector; a firing member;a trigger; a firing drive selectively engageable with said firingmember, wherein said firing drive comprises a rack, and wherein saidrack comprises: a first drive portion, wherein said firing drive isconfigured to engage said first drive portion and advance said firingmember relative to said end effector upon a first actuation of saidtrigger; a second drive portion, wherein said firing drive is configuredto engage said second drive portion and advance said firing memberrelative to said end effector upon a second actuation of said trigger;and a rotatable portion configured to be rotated a first amount duringsaid first actuation of said trigger and a second amount during saidsecond actuation of said trigger, wherein said rotatable portioncomprises a key positionable in an initial position, and wherein saidrotatable portion may be configurable in an activated configuration anda deactivated configuration; a reversing drive selectively engageablewith said rack, wherein said reversing drive is configured to retractsaid rack and said firing member relative to said end effector upon asubsequent actuation of said trigger, and wherein said subsequentactuation is subsequent to said second actuation; and an indexingmember, said indexing member comprising: a first stop, wherein said keyis configured to rotate past said first stop into a first positionduring said first actuation of said trigger, and wherein said first stopis configured to prevent said key from returning to said initialposition when said rotatable portion is in said activated configuration;and a second stop, wherein said key is configured to rotate past saidsecond stop into a second position during said second actuation of saidtrigger, wherein said second stop is configured to prevent said key fromreturning to said first position when said rotatable portion is in saidactivated configuration, and wherein said key is configured to rotatepast said second stop and said first stop when said rotatable portion isin said deactivated configuration and said key is returned to saidinitial position.
 2. The surgical instrument of claim 1, furthercomprising a frame, wherein said indexing member is mounted to saidframe, and wherein said indexing member is configured to rotate relativeto said frame when said key is moved from said initial position to saidfirst position and said first position to said second position.
 3. Thesurgical instrument of claim 2, wherein said frame comprises a recess,and wherein said indexing member is movably positioned in said recess.4. The surgical instrument of claim 1, wherein said indexing membercomprises a spring mounted to said frame.
 5. The surgical instrument ofclaim 4, wherein said spring is configured to deflected by said key whensaid rotatable member is moved from said initial position to said firstposition and said first position to said second position.
 6. Thesurgical instrument of claim 1, wherein said indexing member comprises aplate, a first aperture, and a second aperture, wherein said key ispositioned within said first aperture when said key is in said firstposition, wherein said key is positioned within said second aperturewhen said key is in said second position.
 7. The surgical instrument ofclaim 6, wherein a sidewall of said first aperture defines said firststop and a sidewall of said second aperture defines said second stop. 8.The surgical instrument of claim 6, wherein said plate comprises acantilever including a fixed end mounted to said frame and a movable endmovable relative to said fixed end.
 9. The surgical instrument of claim1, further comprising: a frame, wherein said indexing member comprises aplate mounted to said frame; and and at least one spring positionedbetween said plate and said frame, and wherein said spring is configuredto permit said plate to bias said plate toward said key.
 10. Thesurgical instrument of claim 1, wherein said rack comprises a thirddrive portion, wherein said firing drive is configured to engage saidthird drive portion and advance said firing member relative to said endeffector upon a third actuation of said trigger, wherein said subsequentactuation is subsequent to said third actuation, wherein said indexingmember comprises a third stop, wherein said key is configured to rotatepast said third stop into a third position during said third actuationof said trigger, wherein said third stop is configured to prevent saidkey from returning to said second position when said rotatable portionis in said activated configuration, and wherein said key is configuredto rotate past said third stop when said rotatable portion is in saiddeactivated configuration and said key is returned toward said initialposition.
 11. A surgical instrument, comprising: an end effector; afiring member movable between an initial position, a first firedposition, and a second fired position; a trigger; a firing driveselectively engageable with said firing member, wherein said firingdrive comprises a rack, and wherein said rack comprises: a first driveportion, wherein said firing drive is configured to engage said firstdrive portion and advance said firing member relative to said endeffector upon a first actuation of said trigger; and a second driveportion, wherein said firing drive is configured to engage said seconddrive portion and advance said firing member relative to said endeffector upon a second actuation of said trigger; a reversing driveselectively engageable with said rack, wherein said reversing drive isconfigured to retract said rack and said firing member relative to saidend effector upon a subsequent actuation of said trigger, and whereinsaid subsequent actuation is subsequent to said second actuation; andholding means for holding said firing drive in said first position aftersaid first actuation and before said second actuation and for holdingsaid firing drive in said second position after said second actuationand before said subsequent actuation.
 12. The surgical instrument ofclaim 11, wherein said firing drive comprises a gear train comprising aplurality of gears, and wherein said holding means is configured toprevent the rotation of at least one of said gears.
 13. The surgicalinstrument of claim 12, wherein said holding means comprises a springconfigured to engage a said gear, and wherein said spring is configuredto permit the rotation of said gear in a first direction and prevent therotation of said gear in an opposite direction.
 14. The surgicalinstrument of claim 12, wherein said holding means comprises a pawlconfigured to engage a said gear, and wherein said pawl is configured topermit the rotation of said gear in a first direction and prevent therotation of said gear in an opposite direction.
 15. A surgicalinstrument, comprising: a shaft comprising a distal end; a firingmember; a trigger; a firing drive selectively engageable with saidfiring member, wherein said firing drive comprises: a first driveportion, wherein said firing drive is configured to engage said firstdrive portion and advance said firing member relative to said distal endupon a first actuation of said trigger; a second drive portion, whereinsaid firing drive is configured to engage said second drive portion andadvance said firing member relative to said distal end upon a secondactuation of said trigger; and a rotatable portion configured to berotated a first amount during said first actuation of said trigger and asecond amount during said second actuation of said trigger, wherein saidrotatable portion comprises a key positionable in an initial position; areversing drive selectively engageable with said firing member, whereinsaid reversing drive is configured to retract said firing memberrelative to said distal end upon a subsequent actuation of said trigger,and wherein said subsequent actuation is subsequent to said secondactuation; and a holding member, comprising: a first backstop, whereinsaid key is configured to rotate past said first backstop into a firstposition during said first actuation of said trigger, wherein said firstbackstop is configured to prevent said key from returning to saidinitial position prior to said reversing drive being engaged with saidfiring member; and a second backstop, wherein said key is configured torotate past said second backstop into a second position during saidsecond actuation of said trigger, wherein said second backstop isconfigured to prevent said key from returning to said first positionprior to said reversing drive being engaged with said firing member, andwherein said reversing drive is configured to disengage said key fromsaid holding member when said reversing drive is engaged with saidfiring member.
 16. The surgical instrument of claim 15, furthercomprising a frame, wherein said holding member is mounted to saidframe, and wherein said holding member is configured to rotate relativeto said frame when said key is moved from said initial position to saidfirst position and said first position to said second position.
 17. Thesurgical instrument of claim 15, wherein said indexing member comprisesa spring mounted to said frame.
 18. The surgical instrument of claim 17,wherein said spring is configured to deflected by said key when saidrotatable member is moved from said initial position to said firstposition and said first position to said second position.
 19. Thesurgical instrument of claim 15, wherein said holding member comprises aplate, a first aperture, and a second aperture, wherein said key ispositioned within said first aperture when said key is in said firstposition, and wherein said key is positioned within said second aperturewhen said key is in said second position.
 20. The surgical instrument ofclaim 19, wherein a sidewall of said first aperture defines said firstbackstop and a sidewall of said second aperture defines said secondbackstop.